i had a lucid dream a couple of months ago and this is how it worked:

i was walking down a path next to a highway, but it was like where the tunnels/hills/dips are, you know? but it's an open path with nothing really surrounding me. and i'm just walking. i start to jump uup and down. just for fun. but then in the process of this, either i start remembering my ability or it just happens.... but, everytime i jump in the air while walking along this path, my body lingers in the air for longer than usual. i notice this. then i start jumping higher to see if i linger longer in the air. and that's what starts to happen. then guess what? i start to believe/fee/think i can fly. and guess what? i start to fly. i'm flying over the town over people playing in the park doing their normal everyday deeds. but get this. everytime i start to doubt my ability to fly and start thinking "this isn't possible", my ability to fly disappears and i start to fall towards the ground. as soon as i start to think ic an fly and empower myself again, though, i go back up and start flying again.