Beware of big stainers.
Berries, chocolate, coffee, tea, colas, root beer, red wine and tobacco are known for discoloring enamel. With darkening drinks, use a straw or swallow quickly to limit contact with front teeth.
Hard raw fruits and vegetables such as carrots, broccoli and apples will help scrape away plaque, which makes teeth look dull.
Supplement regular toothpaste.
Use a whitening paste once or twice a week to remove surface stains. Or mix a paste of baking soda and water and brush with it a few times a week (but not daily, as the mixture is abrasive).
Scrubbing too hard erodes enamel. Use a toothbrush with soft bristles and clean with light circular motions. Note: Electric sonic toothbrushes are especially good at stain removal.
Get your fluoride.
Make sure your daily toothpaste contains this mineral, which helps prevent decay. Ask your dentist about rinses or gels that guard enamel.
Be a smart swimmer.
If you're in a pool frequently, look into mouth guards that can protect against chemicals that may damage teeth.
Depending on what whitening method you use, you may need a touch-up treatment every six months or so.