A healthy diet and a change of habits can prevent tooth stains and preserve your pristine smile. Enjoy your favorite foods, but use caution. Moderation is key when it comes to foods and drinks that discolor your teeth. If you choose water over other beverages, and if you make sure to rinse your mouth with water and brush your teeth within a half hour of eating, you can significantly improve your smile. Stay on top of your brushing and flossing, too. Flossing helps remove the pesky plaque that builds up between teeth and the gum line and attracts stains.