For optimal protection, generously apply a generous amount of sunscreen over all parts of your body that will be exposed to the sun -- the mistake many people make is not applying enough. Let it absorb for at least 15 minutes before going outdoors.

Keep in mind that some people are allergic to certain ingredients found in some sunscreens, so it's a good idea to test the product first on a small portion of your skin. (It's not advisable to test it on your face.)

Although some sunscreens claim to be water-repellent or waterproof, you should still reapply every two hours. If you go into the water or participate in any activity that causes you to sweat excessively, you should reapply sunscreen immediately after drying off.

Nowadays, many makeup foundations contain a sunscreen of SPF 15; this can protect you during the day. Lips also need to be protected from the sun; many lip balms have an SPF of 15 or higher.