Watches that rely on gear mechanic can be adversely affected by magnets. Magents are most commonly found in televisions or laptops in your house. Make sure to keep these electromagnetic devices away from your watch. Magnets may effect the metal components inside your watch and will affect its operation.
Take It Off When Doing Exercise
If you are going to do exercises such as tennis or rock climbing it would be a good idea to take off your watch. Leave your watch off to avoid any damage while you are doing exercise. Droping or bumping your watch too many times may damage it's components and surface.
Don't have your watch be in a place where the temperature is either warmer than 140 °F or colder than 32 degrees. Extreme heat or cold can effect the lubricants inside your watch which, allows it to operate.
Have your Watch being check by a professional every one or two year. Cleaning at home by yourself isn't enough, the professional are the one who knows watches the best.