Basic:
Walk through an Art gallery and examine the artwork created by your mind. (Tiktaalik)
Dive through the ground and describe where you end up. (FryingMan)

Advanced:
Crumple up the entire scene in front of you with your hands like it's just a drawing on a piece of paper: describe where you are once you do this. (FryingMan)
Slide down a dream rainbow. (MoonageDaydream)

Bonus:
Travel to Olympus and anger a god/goddess. Describe what happens. (paigeyemps)

I think I'd be interested in trying to get myself to do some tasks if I could get lucid, maybe specific goals are a push I could do with for myself lately. I'd personally be interested in these:
TOTM LDs have traditionally been some of my most stable, vivid, longest, just plain most enjoyable LDs I've ever had. Concrete goals make a big difference in getting lucid! Got lucid last night and couldn't remember any goals, so it was a weaker/shorter LD, boo hoo!