Apply sunscreen liberally and often.

It is important to apply sunscreen and sunblock liberally and regularly. Remember that all skin types are different, and that most sunscreens are only effective for about four hours. Choose a sunscreen with a high SPF, a brand like Ocean Potion, and limit your sun exposure during prime sun areas to get the most protection. You should reapply sunscreen often, usually after towel drying or a work-out is a good time. Use about one ounce (a shot glass full) per application. Apply your first layer of sunscreen at least 15 minutes before going into the sun, and reapply after swimming, sweating or toweling off. Even waterproof sun protection lotions can weaken or be rubbed off over the course of the day, so don´t think you can just apply once.