You can use toothpastes with a whitening effect, usually pastes for smokers, they are more abrasive, rinsing the mouth with hydrogen peroxide diluted 1: 1 with water. All these methods are not as effective as, for example, professional oral hygiene at the dentist, which everyone should do
A question from the series "how to easily raise the dough": D
I can advise you not to smoke and not to drink coffee / black tea, this will save you from pigmentation that visually make your teeth darker)
As for whitening - the safest is laser. And at home you will never come close to the effect that you can get from the dentist in half an hour. But at home there is a chance to get a burn of the gums, strong sensitivity of the teeth and microcracks of the enamel (which, without polishing, contribute to the attachment of plaque and tartar)
Good afternoon. You can whiten yourself, but most likely it will not work harmlessly. You still have to contact your dentist to order a whitening system. Listen to the recommendations and only then proceed. All whitening pastes and gels are not durable and not to say cheap. Better once, but good quality.
I observe oral hygiene perfectly: I brush my teeth in the morning, day and night. Only they are yellow like the sun anyway.