I recall such dreams, and it was occasionally quite difficult to overcome the inertia of beliefs .... almost a physical effort to....overcome belief in gravity
What seemed easiest was to launch myself forward like a glider, leap forward and stay aloft through will-belief. Much like superman typically does.
It felt so real I actually tried this in a park, (once). Someday I expect it'll happen in real life when I absolutely believe it,
Even as I write this, my heart seems to know I've done this, that's it's no more unlikely than walking.
Yet i also recall dreams where I seemed to be tutored, inside a room, and it was much less challenging to float, in the confines of an enclosed space,
Had a dream last night falling from a plane and evidently dying (a first)
To prove I was "dead" I levitated out of the physical form , went thru a wall into a resturant full of other "crossed over" souls.... the afterlife of sorts.
Flapping one's arms doesn't generally work... for me the will-power to fly came from the heart ,rather than the mind. Like something my heart remembered how to do