Sunscreen 101

Of course, no sunscreen in the world will be effective if not properly applied, here are some tips for optimal protection:

Slather up before you hit the sand: "While applying sunscreen any time is better than nothing, it's best to apply the stuff 30 minutes before you plan to be in the sun to ensure it's had time to soak into your skin," says Dr. Linder.

Read the fine print: "Avobenzone, Mexoryl, zinc oxide and titanium dioxide offer the broadest protection for your skin," says Dr. Linder. "Check the label for these ingredients before tossing the sunscreen in your cart."

Perfect your application: Chemical sunscreens, like avobenzone or oxybenzone, should go on clean, bare skin because they need time to be absorbed to be affective," says Dr. Linder. "Sunscreens that act as a physical block or reflector to protect skin (zinc oxide and titanium dioxide) can be applied last, after your moisturizer." Not sure how much is enough? "One ounce [about the size of a shot glass] should be enough to cover your whole body," says Dr. Linder. Try applying sunscreen before you get dressed to ensure complete coverage. "And, water-resistant or not, always reapply every two hours."