Fall by moving away from an area where there is ground under you

Hit F

space bar, does the vertical arc ascension jumpy thingy
(WARNING: this puts you in a place mentioned in section #1. You will fall until those conditions are met.)

If you repeatedly hit space and f you bounce up and down like a kid with a seizure in his legs

jump and use all of the above techniques to avoid fall damage
it can also be used to jump off the map and to safety in boss fights and stuff
try to use it a lot when you are tired of this ♥♥♥♥♥♥ game because ♥♥♥♥ it it's so bad