I've had three lucid dreams where I flew into the air and I believe the easiest way to fly is to expect to fly. In my latest lucid, I jumped out my window and then jumped off the ground and flew. I didn't think about, it was more of a feeling than word thought. Understand?
So next you want to fly in your lucid dream, have the expectation/feeling to it. It's quite simple. Just Jump and Feel the Power.