"How To Whiten Your Teeth On a Budget" How To: Mix a tiny bit of tooth paste together with 1 tsp. hydrogen peroxide, 1 tsp. baking soda, and 1/2 tsp. water. Mix well then brush your teeth really good then rinse. Do this once or twice a week until you have reached the desired results then switch to once a month. I tried it today and saw small, but immediate results..