Always take the house key with you when leaving the house, even for a short period such as checking the mail. It is not uncommon for a customer to be waiting for a locksmith in their bathrobe because they only went to get the paper.
If the keyhole begins to have a rusty appearance or becomes difficult to turn, try minimizing friction and allow smooth movement by lubricating it with a lubricating spray easily purchased from any hardware store. Applying pressure to a key to turn may cause the key to break and needed to be removed from the keyhole by a professional locksmith. A good locksmith will have the locksmith equipment to extract the key, but in some cases the lock itself may need to be replaced.
If you own a locking box, small safe with a key, or have a drawer that locks, never put the key inside the unit. The unit may close and lock the key inside.
When adding an alarm or keyless entry system to your vehicle, ask the alarm technician to disable the auto locking feature. This will avoid accidentally leaving your car keys in the car and the doors locking with the vehicle keys inside. Locksmith training enables locksmiths to open a locked vehicle with minimal damage.
When cleaning or doing regular maintenance to your vehicle, remember to keep the keys outside of the vehicle. If the keys have to be in the vehicle, then wind down at least one window. By doing this you will avoid locking the keys inside the vehicle if all the doors close. A car locksmith will have to open the vehicle in a timely fashion with a locksmith tool.