My teeth are very discoloured how do I get them white again?

well the best way to get them white again will be to see a dentist and have them clean your teeth. and honestly that's most likely the only way you can really get them white, because personally no toothpastes or other products have worked for me in teeth whitening. also avoid drinking coffee or eating foods that wil stain your teeth. but i would say go ahead and get a cleaning at the dentist. they're not that expensive.... i don't think lol. :)