I used to do lucid dreaming, I made what I called "logic gates". Which would just be checking how I got to the place I'm at in the dream. For example, if I'm at a waterfall how did I get there? Where's my car? Do I have my keys/wallet? What did I eat for breakfast?... and so on. However I managed to get stuck in a lucid nightmare, and decided not to do any sort of dreaming again, as soon as I realize it I try to snap back awake again.