Intermediary level trick
This is something that I started doing while lucid dreaming only for the fun of it. Though it may seem easy, it isn't, so I've classified it as an intermediary level trick.
For example, a Beginner lucid dreamer may be able to fly and go through walls. An Intermediary dreamer may be able to paralyze people, reverse time, and walk on walls and ceiling.
The idea is to walk on the wall as if you were walking on the floor. Your body will be horizontal while you walk on a vertical wall. When you are next to the ceiling comes the most challenging part, your body will turn upside down while you walk on the ceiling. It comes in handy when you need to change a light bulb. You can then sit on the ceiling and meditate, upside down.
It is not really an ability, because sometimes I can do it and sometimes I can't. Don't know if it depends on me alone or if there are other forces that allow the trick to be done or not.
Let me know if you've ever done this and how it went, I recommend you try.
My words of wisdom: My only fear is to not act justly.