This may seem like a lot of unnecessary effort for something as small as a lock, but a lock is the main key to safety in your home. After checking your locks for rust and loose screws, take a closer look at your door handle. The handles should not be broken, skew or loose. The handles should be properly fitted, and broken or faulty ones be replaced. A faulty door handle can lead to a broken lock, meaning your safety, and that of your family, is questionable.
When the lock is checked, inspect all the screws, mechanism and door frames/window frames for rust. Rust is a mayor factor to ensure your locks are secure. Rusty screws, mechanisms and door frames / window frames can lead to breakage which can not be seen by the naked eye. Replace all rusty screws, mechanism, door frames/ window frames.