Monthly, carefully observe the door as you open and close it. If you hear or see anything unusual, take a closer look. The regular motion could loosen up some of the hardware, so take a few minutes to tighten everything up. Also, be sure that tracks, tires, and other moving parts are lubricated. If your door is painted, make sure it isn't chipped or peeling. Deteriorating paint on a wooden door could let moisture in, which leads to warped doors, while a steel door could rust.