I used to Lucid Dream when I was in highschool, and I had a lot of tips to help...
You have to teach yourself how to do things in your dream and I had the exact same problem with flying... So, to create things in my Lucid dreams or (LD's) I would say to myself "ok when I turn around there will be a telephone behind me" then boom it's behind me, then I would call my friend jacob and be like yo come over man, and then think "when I turn around he will walk around the street corner" and boom there he is..
so to fly, I felt like I was still bound by physics, but you must realize that you create the physics in your dream... but that will come with time.... so anyways I created a plateform (using the call my friend on a phone methond, aka thinking that when i turn around _____ will be there) that was a circular dick, I would step on the platform, and them make the platform move... then my body would move with the platform... eventually you get rid of the platform etc etc...
to lucid dream often I got a watch and made it beep every hour, and on that hour(this is while awake) I would think to myself "Am I in a dream?" and then scope the room or area that I am in.... sure enough after two weeks, I could lucid dream very eiasly but I would 'white out' in some dreams... So I was told to spin and count to eight, and thats what stops me from whiting out and I can stay in the dream...
also, having a journal and writing down everything about your dreams, lucid or not, will help SOOOOO MUCH... it's very important.. try not to get frustrated too