I’ve read a few people have had problems with flying. Well, before I started having lucid dreams, I already had an answer to this.
The very first flying dream I ever remember having was that I was sumperman’s apprentice. I consulted him about the problem I had of working with him; I couldn’t fly. 
He told me not to worry and gave me a pack of special bubble gum. I didn’t have to blow bubbles to fly, the simple act of chewing this bubble gum was enough. It’s simple, who can’t chew chewing gum? And it’s a tidy little package so it wouldn’t be hard to “imagine” there is some in your pocket in an LD.
Speaking of bubbles, I think I’ll blow some bubbles in my next LD, how cool would that be, they could be so big, and really beautiful, and you could get inside them and float over the country side. 
Sorry, really really getting into this stuff though.
Good luck with flying. Just believe.
