I used to have the same problem, and being a teenage girl i was always very upset about it. Looks are important to me. I was getting so sick of nothing working that i talked to my dentist. He suggested crowns, caps over my teeth, and other things, but they were all expensive and inconvenient. I tried bleaching trays and that didn't even help. Eventually, about 2 years ago, my dentist called one day and said he wanted to experiment and try a new treatment on my teeth. Since this was an experiment, i got to do it for free. What he did was grind off a bit of my teeth(like using a sander) and applied a new paste called MIPaste. I was also instructed to use it regularly as toothpaste. It is supposed to help people with bad coffee stains, and it worked miracles on my teeth. YOu can't even notice the discolored spots anymore. Talk to your dentist about this. It is great.