For yellow teeth, you can start with over-the-counter whitening toothpastes containing active ingredients like hydrogen peroxide, carbamide peroxide, or mild abrasives like silica. For faster and more significant results, I highly recommend visiting your dentist. They can offer professional in-office bleaching using medical-grade peroxide or provide custom-fitted take-home whitening trays. Please avoid using highly abrasive DIY treatments like charcoal or baking soda, as they can permanently erode your enamel. Always consult your dentist first to check for underlying cavities or gum disease before starting any whitening treatment.