Tyler from Toronto, Ontario suggests that when a door hinges screw hole is warn out you can glue in match sticks to fill the hole and then put the screw back in.
Match sticks, tooth picks, with and without glue have been used for years to tighten up screw holes. Sometimes simply putting a single sliver of wood into a hole will help the screw to grip. When the holes are really a lost cause, gluing in a bunch does work. In fact this is much easier to do that trying to fill the hole with a dowel that is never just the right size. You just keep on putting in match sticks or tooth picks until you have filled the hole.
Now a couple of details and precautions. Match sticks are almost always soft wood, tooth picks can be either soft or hard wood. This can be important in that if you jam full a thin soft wood piece of wood with a hard wood plug, you could split the door when you put in the screws. Putting soft wood plugs into a hardwood door will not give you a very good grip. Match the filler to the wood, and if the door wants to crack at all, drill pilot holes. It is also possible to put in toothpicks and glue, not quite filling the hole and then run in the screw while it is wet. It will hold a bit, but once dry will hold well, without forcing anything.