Try these tricks to prevent stains.

• Know the magic number. Brush your teeth first thing in the morning and right before you go to bed for an average of two minutes.
• Use a chaser. Keep a glass of water around to sip (and swish) when eating/drinking staining culprits such as red wine, coffee, blueberries, soy sauce, balsamic vinegar, tomato sauce and certain fruit juices (grape and cranberry). 
• Chew on these. Pack apples, celery and carrots into your diet. Chewing on these foods whitens teeth naturally; think of them as a great skin scrub for your teeth.
• Order a side of greens. Greens such as spinach, broccoli and lettuce prevent staining because they create a film over the teeth that acts as a barrier. So be sure to order a side of spinach along with that glass of wine.
• Find your shade. Red lipsticks can make teeth look brighter, so opt for richer reds, berry tones or reds with subtle blue undertones. Avoid orange-toned lipsticks, which can make teeth look yellowish or dull.

Source: Dr. Jonathan B. Levine