Mine are all around the house symetery issues - towels, pictures, flat surfaces - all must be clean, clear and square, always. So my husband and youngest make it a habit of touching everything every morning while getting ready for work and school. Every towel, picture and flat space will be despoiled before they leave and then I have to spend an hour cleaning and leveling. Cheeky gits!
The worst is leaving for holiday. They do their evil and go out to the truck, then I spend 15 minutes checking everything before I can leave (God forbid a towel is uneven while I'm in Belize). In the end they always ask, "What took you so long?" Boarders on abuse, I'd say.