Carry two sets of car and house keys just in case one set gets locked inside. Keep a third set at home in something that can't be locked.
Colour code the faces of your keys so that you'll know instantly which lock each one opens.
If a duplicate key is difficult to insert or remove, try filing down its rough edges with an emery board.
To straighten a bent key, put it on the face of a club hammer and tap it lightly with a mallet.
When a house key is hard to turn, squeeze a little powdered graphite into the lock and spread it around by jiggling the key back and forth. If you don't have any powdered graphite, scrape the point of a soft-lead pencil over the teeth of the key and insert it into the lock. Don't ever use oil - it will gum up the lock.
If a key breaks in a lock, you may be able to extract it with a pair of needle-nose pliers or a fine, stiff wire.
If you've lost the key to a locked drawer, first see if the drawer above is unlocked; if it is, remove it to get into the locked drawer below. If this approach is impossible, minimise damage by taking off the back of the desk or chest.
Copy the manufacturer's code number imprinted on a new car key or its attached tag and keep it in a safe, handy place so that the car dealer can make a duplicate key for you. If you lose the code, your car dealer may have a record.
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