You can do bleaching, but for that use it very sparely like a lot less than they say to, take what they say on the box and half it. A lot of the over the counter bleaching things are harsh on your enamel, so you need to be aware of that. (Some people bleach too much and destroy their enamel so don't do that.) Just because your teeth are stained that doesn't mean they are unhealthy, but do make sure you get them cleaned by a dentist twice a year. With coffee try using a straw to drink it (be careful it's not too hot) and when you are done just rinse your mouth out with water. Also if you drink carbonated drinks, they are bad for you, even the soda water, because it harms your teeth. As far as cosmetic dentist go, at least I'd rather have my own teeth than veneers, and once you do that you have to commit to them for the rest of your life. That's because it's basically like a filling and they need to file down your teeth to get them to stick. A lot of people on TV have them, but for regular people, it will do more harm than good in my opinion. I'm not a dentist but I'm very ocd about my teeth. >.< My teeth have stain on them because I drink tea a lot, but it's ok. So before you go to a cosmetic dentist go to a regular one and have them clean your teeth, then they can advise you on what to do better. I hope this helps. <3