Trap Guide

Okay, so, basic trapping guide.  I'll try to focus on stuff that's impermanent (that is, focused on traps/CDs/TVs more than TGs); if you feel like you want something a bit more serious, then you should be talking to therapists and endocrinologists, not a stranger on the internet.

The best thing you can do is to research the dimorphism between males and females, since that'll tell you exactly what you want to hide/accentuate.  I'm just going to be summarizing here.

Face:
>Forehead
Male foreheads are flatter and rougher.  If you're growing out your hair (or wearing a wig), bangs are strongly recommended.  If appropriate to your look, a hat or a headband can be even better.  The forehead is just about the biggest facial sex indicator in humans.
>Brow
Going right along with that, the male forehead juts forward a bit more and the eyebrows are a bit lower.  With an electric trimmer, carefully shave along the bottom of your eyebrow (if available, using a detailing head).  And don't try this the first time you trim your eyebrows, but you'll also want to impart them with a bit of an arch so that they more closely follow the curve at the top of the eye.
Glasses can be a HUGE help here.  They also have the added effect of sort of "jolting" your brain into seeing you differently--it can be hard, when looking at yourself in the mirror, to see yourself with a different face, but glasses make it a bit easier.
>Eyes
A bit larger in females.  Ensure you've taken care of dark circles as best you can.
>Nose
Shorter and more upwards-pointed in females.  Though, full disclosure, I'm not sure how to cover this very much.  The glasses help a bit.
>Cheeks
Females, even very thin females, tend to have a bit of fat around the cheeks, covering the cheekbone.  And actually the best way to achieve this effect, as far as I've been able to tell, is just smiling.  And besides, everyone looks better when they're smiling.  Darkish blush or bronzer applied in a large line below the cheekbone will also help.
>Jawline
The male jaw is more defined and angular.  Long hair can cover up the ends and make a big difference on their own.  Oh yeah, and shave very thoroughly, obviously.  If you do well with the rest of the face, the jawline matters less than people think it does.
>Skin
First step: get rid of oily buildup.  Males produce much more skin oil than females, so invest in a good daily cleanser (use every time you shower) and a more thorough exfoliating cleanser (use it twice per week for 2-6 weeks, then once per week from then on).  I can't attest first-hand, but my sister swears by olive oil as a facial cleanser, and it does seem to work for her.
>Lips
Male lips tend to be wider horizontally but shorter vertically--so apply lipstick as high and as low as you can without going off the edge but you might want to stop short of the edges.  Also, be sure to accentuate the "cupid's bow" shape on your upper lip as much as reasonably possible.
The upper lip (space between nose and mouth) is shorter for females.  As with the cheeks, the best non-surgical way to get this effect is just smiling.
>Makeup
The key points to hit: concealer, lipstick, blush/bronzer.  Mascara and eye shadow can actually hurt by making your eyes look smaller.
Unfortunately, I can't help very much with makeup--first of all, because I'm not an expert, but moreso because since everyone's skin and face are a little different, it's hard to know remotely what colors you should get.

>Posture
Females typically have a posterior-mounted pelvis, while males' are anterior-mounted.  Or rotated-further-back pelvis versus rotated-further-forward pelvis, in simpler words.  It's uncomfortable for a while, but training your pelvis into a posterior position makes a HUGE difference.
Your back will be more arched, your legs will look longer and more toned, your waistline will be pulled out more and look slimmer, it becomes easier to tuck in your shoulders, your butt pops more, and I could go on.
Pulling in your shoulders, in my experience, becomes more effective when you realize you shouldn't pull in your shoulders themselves, per se--that is, where your arm starts.  Think about on your shoulder blades, in your back.  They make a better focus, and if you shift your body with the goal of moving your shoulder blades closer inwards towards your spine you'll do a better job achieving narrower feminine shoulders.  If that makes sense.

>Shaving body hair
If you've never shaved before, expect to go through several razors on your first go.  While admittedly I was using very cheap razors and I was rather inexperienced with shaving in general, I went through a pack of 10 my first time.
I should also mention that I've got super, SUPER sensitive skin, so my full process might not be necessary for you.
Start by applying a coat of shave gel.  Shave once with the grain.  Run the skin under cool water for a few seconds and lightly scrub with a loofah or washcloth.  Now apply conditioner instead of shave gel and shave again, against the grain.  Run skin under cool water, then apply a moisturizing lotion.  Move on to the next area.
Though keep in mind that unless you're on hormones, male body hair grows in much more quickly than female body hair.  You'll probably have to do this every few days if you want to keep up the look.
In particularly thick areas, such as under the arms, run an electric razor over the area first or trim it with scissors.

>Clothing
This is, to me, the fun stuff.  I just love clothes.
So, just general stuff: know your measurements.  The key six:
>Bust
Wrap a tape measure around the fullest part of your chest.  If you're planning on wearing a padded/push-up bra, get your bust measurement while wearing it, as well.
>Underbust
Since you probably don't exactly have a "bust", this is a bit fuzzy, but it's approximately at the bottom of your ribcage.  If you can clearly visualize where your boobs would be if they existed, then measure underneath where they'd be.  Since your first bra or two should probably be cupless, you've got some wiggle room.
Worth noting that this is NOT your band size.  If you're shopping for bras, here's a good guide: http://youtu.be/UoqXCnYOwCI
>Waist
Stand in front of a mirror and lean to the side until you see a "crease" in your skin.  This is your natural waist, not to be confused with your pants waist.  For this measurement, the tape should be comfortably loose.  If you're on the leaner side, you may be able to simply see your waist, at the narrowest point on your body.
>Hips
Measure at the fullest point.  And finally,
>Height
Doesn't come up a ton--skirts and dresses are more forgiving of varying heights than pants, for example--but keep it in mind.

I might as well take this chance to mention your waist-hip ratio.  Basically divide your waist measurement by your hip measurement; it's a big visual factor in identifying sex.  For healthy males, it's generally about 0.9; for healthy females, while it depends on race and country, it's closer to 0.7.  If you like, you can purchase pads online which you can wear to give your hips and butt a fuller profile--google "hip pads" or "hip padding" and find one that suits your fancy. (I can't give first-hand advice here, unfortunately.

>Underthings
Shapewear is your best friend.  They've got shapewear to make your waist thin and to make your curves kickin'.  Though it can be pretty expensive.
Unless you've already got very pronounced moobs/boobs, avoid anything with a firm cup--this means if you're looking for something to slim your waist, look for underbust corsets, not bustiers (which are often mistakenly called corsets).  Also note whether the corset is bone-in (meaning it has a rigid frame, usually made of metal) or not, since bone-in corsets provide a more dramatic waist-slimming effect but are also quite a bit more conspicuous.  Also, quite a bit more uncomfortable--though it's worth noting that if you're wearing heels, a corset will actually be more comfortable.  I'll explain why in a bit.
Key panty styles:
>Bikini
The most popular style worldwide, so this is where you'll find most of the cutest designs and styles.
>French cut
Cut like a brief, but with longer legholes.  This is a very good thing for you.  If you're not sure what your "best feature" is, it's probably your legs since, for some reason, even though society likes women with long legs, males actually have relatively longer legs, and french cut panties call attention to yours.
>Boyshort
Fuller coverage, which is good for those with... stuff... they need to hide.  Despite the name, not especially boyish, and make your butt look cuter.
>Thong
Believe it or not, you can pull these off.  Barely There, for instance, produces a microfiber thong with a lot of stretch.  Though you'll only really need them if you plan on showing them off--while, in theory, they're to be worn under especially tight clothing to avoid panty lines, you can also buy laser-cut or seamless panties in any other style which fill the same niche.  Though if, like me, you just like the feeling, then go right ahead.
>Tanga
Boyshort in front, thong in back.  The mullet of panties.

For reasons unknown to me, no pantyhose company publishes a useable size guide online, only on their boxes.  I've taken a picture of the Hanes size guide.

>Tops
Your top should, ideally, help trace a smooth curve from your waist to your hip.  If no such curve exists on your body, go with a looser, flouncier blouse.
Shoulder width produces a troubling game of chicken: it's usually good to avoid sleeveless tops, but if you're bursting at the seams of a sleeved top, that'll call even more attention to your shoulders.  Invest in a couple fashionable jackets.
If you're looking at a size chart and you can't find a size that matches both your bust and your waist, go with the size that fits your bust.

>Skirts
Once you switch to skirts you will never want to go back.
Quick vocab lesson: skirt lengths are usually described as mini (down to the mid-thighs), midi (at the knee or just above or just below), or maxi (all the way to the ankles), roughly speaking.
In general, loose skirts are better than tight skirts.  Loose mini or midi skirts, worn at the right height, will flare out and greatly accentuate your hips, and they're a bit more versatile as clothing items.  Tight skirts also risk showing bulge.  However, if you particularly want to show off your ass, then tight skirts are just fantastic.
So since, as previously stated, your legs are likely your best feature, mini/midi skirts let you show them off.  However, if you've got a narrower waist and wider hips then a maxi skirt can make for a sweet, girly profile.
If you're looking at a size chart and you can't find a size that matches both your waist and your hips:
-if you're searching for a loose skirt, go with the size that fits your waist.
-if you're searching for a tight skirt, go with the size that fits your hips.

>Dresses
High risk, high reward.  If you've got a reasonably girlish form, a dress can make you look particularly feminine.  I generally suggest aiming for about knee-length.  I suggest this because of the way dresses flutter when you move around.  Too long and there's too much weight, too short and there's not enough surface area.
Alternatively, a generously-cut maxi dress is a way for those with less-than-ideal figures to still look and feel pretty pretty.
If you're looking at a size chart and you can't find a size that matches your bust, your waist, and your hips, the waist is generally the most important measurement.  For tighter dresses, hips may be moreso.

>Shoes
For the purposes of this section I'm assuming you do not have unusually small feet for a male.
It's not quiiiite this simple, but in general you can convert men's sizes to women's sizes by adding 1.  E.g. if you wear a men's 9, you'll wear a women's 10.
You want heels.  Remember that thing I mentioned about pelvis mount?  Wearing heels and standing upright will naturally force your pelvis into a more posterior position.  While this might hurt your back for a while until you start getting used to it, the fact that you've got longer feet than the average female means you can wear higher heels without as much foot pain.
Avoid pointed-toe shoes, which will make your feet look larger.  Choose something with a rounded toe or an open toe instead.

>Coordination
A problem I see sometimes is the mentality of "I'll just grab a bunch of cute things and wear them together!"  No.  That works for interior decorating--it's called the "eclectic" look--but it does not work for clothing.  Coordination is key and one of the biggest areas I see outfits falling apart.
When assembling your wardrobe, ensure you've got a few pieces of each kind (so a few tops, a few skirts, a few jackets) that are rather plain.  Either solid colors or non-intrusive designs.  Then when you get especially cute clothes, unless you've planned ahead to specifically pair them with something else, pair them with something simple.  It keeps your outfit from seeming too busy or forced.  You only really NEED one "oh my God, I love your X!" per conversation.  More than one is nice but not needed.
When planning outfits, think of them in terms of "when/where would I wear this?" as a guideline to avoid awkward combinations, like tights with a sundress or a toque with a skater skirt.  The "when" in that question should include both time of day and time of year, by the way.

>Hats
Can be super helpful in covering your forehead and changing the general shape of your hair.  Remember that according to fashion laws, wear straw hats in summer and felt (or other fabric) hats the rest of the year.  Wool should generally be saved for winter.  In the Victorian era and onward, this transition was actually celebrated with the semi-official holiday Straw Hat Day, though its role as the cultural advent of summer (the way the solstice is the scientific and literal advent of summer) was supplanted in time by Memorial Day, which it fell near.
But this is a guide for crossdressing (or gender-affirming dressing), not for my irrational obsession with a long-dead holiday.  The point I was trying to make is that the disappearance of Straw Hat Day is all Kennedy's fault for effectively killing men's hats as a mainstay of fashion.  You've all seen the pictures--dozens of men on their way to work in their trenchcoats and fedoras, no one thinking anything of it.  Kennedy was the one who destroyed that, since he never wore a hat but was well-known as the youthful, hip president, despite being only four years younger than his opponent Richard Nixon, and always at the center of the cultural eye it was inevitable that people would try dressing like him.  He was actually the first president who didn't wear a top hat while being sworn into office, did you know that?
Really the biggest thing keeping the informal men's hat down is its association with neckbeard-fedora-atheist-miladies who don't seem to understand that, no, a fedora does NOT just go with whatever you're wearing.  I saw a guy at work just a couple weeks ago with a fedora and by God he looked awesome.  But that's because he was wearing a sleekly-tailored suit in a stylish lustered grey, bold green shirt and tie underneath, well-groomed mustache the same salt-and-pepper as his modestly slicked-back hair.  The fedora is supposed to go with suits, dammit.  The only person who'd wear, say, a necktie with a T-shirt is the Nostalgia Critic and is that really the example you want to follow?  And in case you were about to answer "yes", the correct answer is "no".
I swear to God I'm not making this up--I know the guy responsible for the current fedora explosion.  It would have been back in 2005.  Except I know that guy, and he's very well off (or at least he was at the time) so he always wore it with pretty nice clothes.  Also, he was 12 at the time so you expect some degree of "this is my trademark".  Kids do stupid stuff to feel special at that age.  But then some people started mimicking the hat instead of the whole picture, then they gave it up but some other kids picked it up and it spread outwards like a faintly creepy shockwave, and each time the people wearing it would be slightly older.  I watched this happen.  By the way, the original guy fazed out the fedora around Freshman year of high school.  And I feel like I have to swear to God I'm not making this up again because he's currently working full-time, living on his own, and dating a girl who's a literal model whom he met when they were both dressed as Rarity at an MLP convention.  I swear to fuckin' God.  If Batman grabbed me from the street I'd swear to Batman.  Though I suppose that leads us to bronies which seems a natural enough segue back to people who ruin fedoras.
If you want to roll out of bed and pick up a greasy black T-shirt with a witticism that's far too long to actually be witty on it from your pile of greasy black T-shirts with witticisms that are far too long to actually be witty on them on the floor, pull on some cargo shorts so you've got room to carry your Doritos, and walk out the door without showering, then that's your business, but when you throw an overwrought smack of out-of-place felt on your head and think it somehow makes you stand above the crowd in fashion then you're not just sloppy, you're sloppy and stubborn and smug.  I can forgive "just sloppy".
See, if men's hats were to make a comeback in our current fashion climate, then you STILL wouldn't wear a fedora with a casual outfit.  You'd wear a baseball cap or a ski cap or something else appropriately casual.
Now, with women's hats, you've got sort of the opposite situation, where it's no big deal to wear a hat casually but it seems out of place in a formal setting.
To put it succinctly, wear summery hats with summery outfits and wintery hats with wintery or nighttime outfits.  A straw hat should be for shorts, sundresses,  and skater skirts.  Beyond being straw, style doesn't matter a ton--it might if you're digging through your local thrift shop, but most hats sold by reputable hat dealers will be of a fashionable style.  Color coordination may still be necessary.
Then that leaves felt hats for evening wear and cold-weather fare--any time you might wear a coat.

Preferred/recommended vendors:

>Clothing
I'm personally a huge fan of Forever 21.  So much so that if you see someone else plugging it in another thread, odds are good it's me.  It's cute, it's cheap, and by God are they on top of their shipping.
A lot of mid-high-end fashion is cut to better fit taller, slimmer (i.e. less curvy) women, so you're actually in luck there.   Michael Kors, Ralph Lauren, and Anne Klein are good places to start if you've got enough money to spare.

>Lingerie
You might notice that Forever 21 sells lingerie, but I don't recommend it--the crotches on the panties are all very narrow.  Instead, check out Freshpair.com and Herroom.com.  Freshpair offers free shipping throughout the U.S., and Herroom very openly acknowledges that men may buy their products.  I'd recommend looking into Barely There lingerie to start with (it's plain, but it's practical and utilitarian) and Maidenform shapewear.  Both Freshpair and Herroom also sell men's furnishings, which works as a good cover if you don't live alone.  Just order something large like an undershirt with your lingerie so when the package arrives, if someone asks "so what'd you get?" just say "oh, an undershirt" and you've got the undershirt to prove it.
I also like Jenni brand panties, but as far as I can tell, they are only available in stores (specifically Macy's), not online, so they're not for the shy.
Hanes bras aren't fantastic, but they are very, very cheap.  Same goes for their pantyhose and stockings--if you want something on the sexier side, I'd suggest Hue.
A company called Fashion Forms produces a silicone bra-stuffer (or "enhancer") which I'm personally a fan of, since it brings me up to almost a B cup and looks pretty real.  If you're going with a good-quality enhancer like that, aim for cupless or removable-cup bras, such as training bras/bralettes or sports bras.

>Cosmetics
E.L.F.  Though truth be told this is where I'm definitely not an expert; I'm mostly recommending based on price, and because Forever 21 lipstick just falls apart like it's nothing.  E.L.F. can be bought online or in many large chains, such as Target or Walgreen's.

>Shoes
Payless is particularly size-inclusive; I believe they stock women's sizes up to 13 (about men's 12) and usually carry wide sizes.  Working in the shoe department I've noticed Jessica Simpsons shoes, produced by Camuto Group, also tend to be well-stocked in larger sizes, but they also tend to be butt-ugly.
I've also got a grudge against Aldo but that's for personal reasons.

>Jewelry
This is personal taste speaking, but I prefer simpler, cleaner jewelry, so brands like Alfani, Robert Lee Morris, Bar III, or Gianni Bernini.  Though this depends on the look you're going for.  Fossil, Lucky Brand, or BCBG, for example, might make you look a bit more down-to-earth.  Tommy Hilfiger or Guess might make you look more flamboyant and bold.  Betsey Johnson might make you look creepy.

>General
In keeping with my advice to stock a few simple items, many larger stores will have EDV items, which you might have seen before.  They're simple, they don't change out with the season or go on sale, and their prices end in .98 and are usually on the cheap side.  If you can't find something better on clearance or in a cheaper brand, root out some EDVs for your filler articles.