Well. I do have to remind you that I am no expert in this stuff either. In many situations, there’s also a certain element of luck involved with marketing. But still, I’d like to try and be helpful, and as such I’d rather point my advice in the ways of questions:
• Have you posted on the different communities for the type of games you’re trying to appeal to (namely the NSFW)? Even in SFW-centric communities, there’s a lot of communities that still accept NSFW stuff and are interested in it. A lot of our traffic for W&S came from r/webgames, surprisingly.
• Does the stuff you show highlight what you’re effectively trying to ‘sell’? Is the impressive technical standpoint of your game visible as a unique sell-point through the stuff you show? Is it working? If not, what other stuff can you show to the people (namely through gifs) that makes people go “Aha! This is the game!”
• Have you made social channels for your game? While NSFW is more limited in the palette of options, Twitter still has one massive NSFW community (not to mention gamedev in general) that follows each other and is still a viable choice. I believe someone mentioned Pornhub as a great place for trailers and posting stuff as well?
• Do you interact with other developers and enthusiasts? Kind of a circling question since that’s what you do here, but always try to find people outside of the enclosed circle. On Twitter for example, every Saturday we always go on #screenshotsaturday and #cutiesaturday tags and talk to the people posting there, and a lot of the times that creates a connection where they either end up following you, or you get some new inspiration for something new. When people ask for suggestions of management games, provide a list of games and don’t be afraid to plug your own (coughs loudly at @HentaiWriter).
• Is there something you can provide alongside the community of your game that might get people interested? For example, in our Discord, we have a #creative room for art that’s as popular as the #gaming room because we attracted artists there, and because there’s always feedback being switched around, people coming back (and also leads them to interact with our stuff) rather than go-and-drop like it happens in most Discord.
• Is there a way you can “sugar coat” some people to promote you/your game? It goes back to the idea of the “code commissions”, but it can honestly be done in many ways. Commissioning art to artists to showcase your game, making fanart of others, having characters crossover with other games, between other options.
• Etc. There's really many ways to go around this.
I comprehend that marketing is frequently annoying and demotivating (I’ve been often demotivated because stuff we posted used to get 5< interactions) and also know a friend who’s an incredible artist that barely gets any attention as well. Our artist is also a master’s in marketing but is just as mind boggled at how some stuff works and other doesn’t. Unfortunately, that’s just part of it. Nowadays just being a good artist, developer or having an interesting game doesn’t just cut it, and a lot comes from properly balancing the creative life with the marketing side of it, and a lot of it is just brute-forcing. :person_bowing:
I recall HW actually made a list of possible places to share your game through before, let me see if I can find it as well.
Here they are!
https://discordapp.com/channels/288047983969435661/288047983969435661/619978511486287903
https://discordapp.com/channels/288047983969435661/288047983969435661/619978893599703060
Just remember, especially in the Reddit case that there's a difference between posting and spamming. I know someone who I warned in advance about their methods (who stubbornly defended that it gave him the same results anyways so why bother) that always posted "[title of the game] [version]" in some 5 subreddits at the same time whenever he updated the game (even if it was a font-change), with no sugar-flavour, or sugar-text, or anything, and surprise, he's shadowbanned in a bunch of places now due to tasteless advertising (including r/gaming).

About the promotion:
I'd say it depends a lot on what your goal is. In my opinion, at your early stages of development, I think you're better off trying to get people to focus either on the game (either hosted on someplace or your own webpage) and hopefully attempt to convert them over to Discord members. Once you're confident that your audience is hyped/willing enough to support development, and you have gained their trust, I'd then move on to actually go through with the Patreon.
One feeling I get when checking Reddit and other places lately is that players have become fatigued of seeing people putting up Patreon up right from their first interaction, and in games that still don't have any ground breaking mechanics before starting requesting for money. There's nothing wrong with Patreon or anything of the like, but shoving it in player's throats from the get-go doesn't seem to be the most advisable choice from the start. Each thing at it's time. :stuck_out_tongue_winking_eye:
When to Start Patreon:
What I said above. But again, that's my two cents on the matter. Other people can tell you otherwise. I don't have a Patreon running yet to give you full stats. :person_bowing:
What channels:
This is coming from someone that mostly did SFW games until now, but if I had to make a downscale to NSFW I'd say to keep the Reddits in check, and I'd aim for Twitter as well (as long as you also try to create connections with people posting NSFW). You also have the usual game portals. I'd say Itch and Game Jolt, and Newgrounds especially if you have a web version. They also have News sections you can use to hopefully propagate a bit more. I'd check the list of websites that HW has posted too. As for forums, people have given good testimony about F95, LOK Forums, LoversLab. Don't have many experience with those, but I'd look at HW's list and see what fits the community you're trying to build.
I'd say you can also double-edge certain places like deviantART and Hentai Foundery if your game as a lot of unique art that would be interesting to see outside of it too. :blobnomcookie:
And I'll go an extras-step and say you could even use certain SFW-only places like Facebook if you already have people you know there - assuming they're comfortable with these themes - and are smart with what you post. Don't go post NSFW stuff there, but hey, Nutaku has a full-running page there, so it somehow can work?

How often to post:
I honestly don't have a good metric for this. There's been a time we were trying posting on Twitter three times a week, there were others I tried to post once I had anything decent. The former didn't work great (and would consume way too much devtime), the latter works somewhat but not ideal. I'd say the rule of thumb is to post whenever you feel you have a milestone (be it a complete artwork/CG you'd like to share or ask feedback on, a new build, an important update) on places like Reddit, and if you do go with Twitter, do #screenshotsaturday and try to keep it up weekly.

Collaborations:
I'd say this one is also arguable. It depends on what you think you can make and the best way of collaboration. If you've got art skills, there's always the possibility of some artwork cross-promotion. If not, I'd go back to what HW said when this conversation started and study what other people could be interested in doing. :sparkles:

Also as far as places to post
Forums to post on (Some places here are friendlier than others)
https://f95zone.to/
https://ulmf.org/
https://rpgcodex.net/ (I have a special perk here to post about my NSFW games I earned by beating the moderators in a Unreal Tournament match, per forum rules, so not 100% sure they will allow everyone else to do the same, but you can try)
http://forums.hentai-foundry.com/
https://forum.fenoxo.com/
https://www.loverslab.com/
http://pornhub.com/ (post your game trailers and montages of your animations here)
https://tfgames.site/ (has a section for non-transformation fetish stuff, but will benefit most if your game has some form of transformation)
https://lemmasoft.renai.us/
http://www.hongfire.com/
https://www.undertow.club/ (seems to possibly be down?)
https://legendofkrystal.com/forum (is currently down but should be back up soon)
https://itch.io/ (post your game here and post on the forums too)
https://gamejolt.com/ (same as above)
https://www.newgrounds.com/ (also same as above)
https://www.fakku.net/forums/visual-novels-and-eroge (not sure on their policy with self-advertising though)
https://vipergirls.to/
https://acg18.life/ (chinese forum; use google translate and register an account, most of the posters like hearing from the devs)
http://the-new-lagoon.com/
https://disboard.org/search?keyword=hentai&sort=-member_count (can search here to find other discords to promote your stuff in)
http://pornolab.net/forum/ (russian forum, same general statement as the chinese forum up above)
https://board.world-of-hentai.to/forums/h-games.24/ (german forum)
http://25rrrr.bbbb333.net/2048/thread.php?fid-66-page-1.html (another chinese forum)
https://milovana.com/forum/
http://www.anime-sharing.com/forum/
http://www.badkittygames.net/community/
https://www.sinicalanimenetwork.com/forum/game-developer-corner

Reddit subreddits (make sure your content is relevant);
https://www.reddit.com/r/NSFWgaming/
https://www.reddit.com/r/Adult_Gaming/
https://www.reddit.com/r/HENTAI_GIF/
https://www.reddit.com/r/visualnovels/
https://www.reddit.com/r/hentai/
https://www.reddit.com/r/Tentai/
https://www.reddit.com/r/hentaibondage/
https://www.reddit.com/r/uncensoredhentai/
https://www.reddit.com/r/DirtyGaming/
https://www.reddit.com/r/TheGameCave/
https://www.reddit.com/r/gaming/ (NSFW stuff does show up here from time to time)
https://www.reddit.com/r/NSFWGames/
https://www.reddit.com/r/XXXGames/
https://www.reddit.com/r/nsfwdev/
https://www.reddit.com/r/lewdgames/
https://www.reddit.com/r/AnimatedPorn/
https://www.reddit.com/r/PixelArtNSFW/

A list of HTML5 sites that propogate games
- http://www.newgrounds.com/ (obviously)
- http://wetpussygames.com/
- https://www.hornygamer.com/
- http://gamcore.com/upload (this one seems to let you just upload right off the bat)
- http://www.2adultflashgames.com/
- https://www.stripskunk.com/
- https://fckps.com/ (this one MIGHT just be their own games, not sure
- http://www.gamesofdesire.com/
- https://h-flash.com/
- https://www.hentai-gamer.com/index.php
- https://adult-sex-games.com/
- http://www.free-strip-games.com/
- http://www.iluvtoons.com/ & http://www.hentairider.com/ (looks to be identical)
- http://playporngames.com/
- http://www.pornogames.xxx/
- https://mysexgames.com/
- http://www.porngames.com/
- https://www.sexyfuckgames.com/