yesterday my girl friend and i were talking about lucid dreaming, and she said that she wanted to fly, now out of all my lucid dreams this is one thing that i have never been great at unless i am very lucid. she told me to imagine the feeling of skydiving, as we have both been, and use that feeling of falling/ floating but use it in the other direction, ie up.
So i tried it last night and it worked like a charm, but in parts i found my self flying too fast upwards strange expereince. but after a while i got the hang of it. Give that one a go.