If a Screw Is Loose in Wood, Use a Toothpick and Wood Glue

When a screw spins freely, the wood fibers around the hole have stripped and there's nothing left for the threads to grip. Dip a toothpick or two in wood glue, insert them into the hole, and snap them off flush with the surface. Wait a few minutes for the glue to get tacky, then re-drive the screw — it will hold tight again. This works on furniture, door hinges, cabinet hardware, and anything else screwed into wood.