Silly Putty, Chocolate, deck of playing cards, paperbacks, a jump rope, if they are into a sport, something to go with that, like a pack of golf balls & some tees or a can of Tennis balls & silly looking socks.
My brother and I started doing a stocking for our Mom when we were teenagers and these were some of the things we put into hers. Now all the adults in the family get a stocking from "Santa" too.