Clean your mouthguard by washing it with soap and warm (not hot) water.
Before storing, soak your mouthguard in mouthwash.
Keep your mouthguard in a well-ventilated plastic storage box when not in use. Make sure the box has several holes so the mouth-guard will dry.
Heat is bad for mouthguards, so don’t leave it in direct sunlight or in a closed automobile.
Don’t bend your mouthguard when storing.
Don’t handle or wear someone else’s mouthguard.