In the case of a Cessna 152, make sure the stupid catch on the seat slides is fully functional, or the seat may slide back and interesting things happen.
I have had this happen, it was really quite disconcerting.
I'm very glad to say that I had another qualified pilot sat in the other seat, who did as he was told when I shouted "Mike, you have controllllllllll" as I shot towards the rear of the aircraft.
G