Buff stains away with baking soda
Whether you're new to the world of tooth whitening, or it's becoming an old habit, you probably already know this one: Baking soda will help brighten your smile.
This trick is an easy at-home stain remover. Mix baking soda and lemon juice into a paste. Brush the paste onto your teeth with a toothbrush, wait a minute, then brush thoroughly to remove. The baking soda, or sodium bicarbonate, will help remove surface stains from your tooth enamel while the citric acid in the lemon juice has a bleaching effect.
If you have sensitive teeth and gums, baking soda can be used alone to remove stains, or it can be mixed with salt to do its stain-removing trick.
Take note: This whitening method can be abrasive, which means it may damage your tooth's enamel if you aren't careful. Buff no more than once per week, and don't let the mixture sit on your teeth for more than one minute at a time.