1. Brush at least twice a day with a whitening toothpaste: Brushing with a whitening toothpaste that contains baking soda, hydrogen peroxide, or other whitening agents can help remove surface stains and brighten your teeth.

2. Swish around hydrogen peroxide or apple cider vinegar: Swishing with hydrogen peroxide or apple cider vinegar diluted in water can help to remove surface stains, kill bacteria, and naturally whiten your teeth. Be sure to rinse afterward with plain water to prevent the acids in these liquids from eroding enamel.

3. Use a homemade baking soda paste: Baking soda is an effective and natural way to remove surface stains and brighten your teeth. Mix together one teaspoon of baking soda with two teaspoons of water to form a paste, then brush on for two minutes before rinsing off with water.

4. Invest in professional teeth whitening treatments: Professional treatments such as bleaching or laser therapy offer fast and effective results, but should only be done by an experienced dentist or oral health specialist due to potential side effects if done incorrectly.