> Z and Shift+Z change the symmetry (Always design with symmetry where possible, and note how your symmetry can change when you decouple previous stages!).
> X changes the angle snapping.
> Alt + click on part on a craft clones that part and anything connected to it, except things 'above' it.
> Shift + click lets you reposition the craft as if you'd grabbed the command pod.
> WASDQE lets you rotate parts.
> Shift + WASDQE lets you rotate parts in smaller increments.
> Action groups are useful. To add something to a group, click action groups (near top right) and then click the group you want to add it to (eg 1-0), then click the part you want to add to the group (eg your solar arrays, parts added in symmetry are all added when one is clicked) then select which action you want to perform with that action group. Toggle is most commonly used. Custom 1-0 are bound to the number keys. Abort is bound to backspace.
> The Clamp-O-Tron Jr. can only dock with other Clamp-O-Tron Jr. docking ports. All other docking ports can dock with each other.
> The HubMax Multi-Point Connector does not have docking ports on it. These must be added separately.
> The arrow on decouplers points to the part that will be detatched. The decoupler will remain on the side the arrow is facing away from.
> The arrows on fuel lines show which direction the fuel will be pumped, the first part you click pumps fuel out and into the second part you click. Useful for asparagus staging.
> Capslock toggles fine movements.
> Alt + WASDQE adjusts trim (changes the "centre point" of the controls so you can fly your plane ascending without having to hold S).
> Alt + X resets the trim
> X sets your throttle to zero immediately, cutting all engines.
> Alt + ., uses physical time warp (craft aren't put on rails, can be used in atmosphere).
> C changes camera modes. Some internal views have a radar altimeter that shows you height above ground instead of sea level that the main altimeter uses (useful for landing).
> Hold the right mouse button and drag to move the camera off-centre. (this has been changed to middle mouse+drag)
> Double middle click to return the camera's centre to the craft's centre of mass.
> V changes which kerbal you are piloting from.
> U toggles lights on and off, lights consume electricity.
> G toggles all landing gear and landing legs.
> ] and [ switch to previous and next craft.
> F1 to take a screenshot. Goes to KSP\Screenshots, this directory won't exist until you take one screenshot.
> F2 to toggle GUI elements (altimeter, navball, staging etc.)
> F3 to toggle the flight results window.
> F4 to hide craft markers (diamonds with names underneath).
> You can target another object by double clicking on it when it is within visual range (2.5km) and you can target individual items by right clicking them and selecting target.
> You can dock more precisely when you shift to docking mode (bottom left, 2nd option, below staging) and it is recommended to right click your docking node and click 'control from here', treating that point as the center of your ship for measurement purposes.
> Enter docking mode when driving rovers to avoid SAS/pod torque flipping them over. This also changes RCS controls, so typically you will want to turn RCS off when you are driving a rover that is not RCS-powered in docking mode.
> When craft are docked, right-click on a tank of fuel/monopropellant/a battery and then Alt+right-click on another container of the same type to bring up the resource transfer menu.
> Shielded docking ports must be opened by right-clicking on them before they are able to dock.
> Make sure your centre of mass is in front of your centre of lift, otherwise your plane will flip out. Front fuel tanks drain first, shifting the centre of mass backwards, so make sure it is still in front of the centre of lift in this case. Raising the height of your center of lift will also help with stability if your lifting surfaces are on the front and rear of your plane, respectively. If you just have central wings, it will probably be detrimental.
> To get an SSTO to orbit, ascend rapidly to 10km, then level out. At this point your speed should shoot upwards. Ascend slowly to 20km, using RCS to keep your nose pointed forward. When your intake air is approaching zero, ignite the rocket engines. This will increase your speed enough to get more intake air. Once this intake air is about to run out, disable the atmospheric engines and the close the air intakes (use an action group for this). You should be at around 1,600 m/s by now. Use the rocket to point you straight up and out of the atmosphere, then circularize.
> Hold shift to run while on ground in gravity. You can also hit Alt to toggle movement mode between run and walk.
> Press space to jump, be careful when on extremely low gravity bodies such as gilly, as a jump there can take 3-4 minutes to complete.
> R turns on RCS, your Kerbal will grab his thruster controls, then you can thrust around.
> L turns on lights.
> Holding the left mouse button and dragging lets you rotate your kerbal (useful for aligning with ladders). Q and E also have this function, though it may be only while using RCS.
> Holding shift with WASD on a ladder lets you lean in that direction. Pressing space while doing this lets you jump off the ladder in that direction.
> To delete all debris, go to settings and set persistent debris to 0, then start a flight, then reset the debris to what you had it to before. This can greatly help with performance, especially if you have the 'stutter' bug.
> Alt + Shift + F12 opens the debug menu in the VAB, and allows you to cheat/place parts without collision (useful for putting probe bodies inside discarded stages so you can switch to and delete them when no longer needed for manual debris removal) and see what crashed your game.