[T16skyhopp]

for loose ball and socket joints that you can pop apart, i just put a tiny piece of paper in there.

If you need to build up a part, like a peg, or need to work something into a joint you cant dissassemble, I hear Pledge clear floor polish with "future" finish is really good. It can be washed off if needed and it's supposedly less chemically damaging to plastic than super glue. Have yet to get some myself though. Clear nail polish is used by lots of people as well.