Yo.
Why not just command gravity to become normal, or find a switch to switch it to normal one?
Either way you might want to work on dream control, here's tutorial for that: Dream Control Tutorial - Lucid Dreaming - Dream Views .
If you are worried about stability, you should learn some stabilization techniques, there are some here: Dream Stabilization and Clarity Tutorial - Lucid Dreaming - Dream Views .
Good luck!