When you want whiter teeth, talk to your dentist. They'll be able to offer you a service which works quickly, and then they can give you a plan which will ensure your teeth don't go back to their butter-yellow days. You should also avoid drinking coffee and red wine, of course.
Make sure to floss daily. Too many people skip or forget this step, and it is very important to your dental care routine. You get food and bacteria stuck in between your teeth. A toothbrush can't reach deep in between teeth to remove them. You need to floss at least once a day to prevent dental issues like bad breath, gingivitis, enamel wear, etc.
If you need to have a dental procedure, try not to stress out about it. Many people avoid visiting the dentist because they are afraid of what the dentist may say, or what may need to be done. If you avoid going to the dentist, you may end up with bigger problems than what you originally had.