Although each 7.5-by-8 inch wipe has enough sunscreen for an adult, there's a high potential to apply too little. "At the end of that wipe, when it's drying out, there can easily be uneven application," Rostan says.

Easy to apply to hard-to-reach areas. "No-rub sprays are great for reapplication, especially if you have sand or dirt on your skin," Rostan says. "They're also good for balding scalps and ears."

With cream, you can see where you're putting sunscreen, which means you get more even coverage. The recommended amount is about one ounce for an average-size body, says Rostan. "Creams also tend to be more water-resistant."

You need a sunscreen with a sun protection factor of at least 15 (30 is preferable) that's labeled "broad-spectrum," according to the American Academy of Dermatology. That means it protects against both sunburn-causing UVB rays and skin-aging UVA rays.

There are many ingredients that provide broad-spectrum protection. Look on the label for benzophenone (oxybenzone), cinnamates (octylmethyl cinnamate and cinoxate), sulisobenzone, salicylates, titanium dioxide, zinc oxide, and avobenzone (Parsol 1789).

Apply at least one ounce of sunscreen 30 minutes before going outside. "One of the biggest mistakes people make is applying sunscreen when they get to the pool or beach, rather than ahead of time," says Dr. Elizabeth Rostan, a dermatologist at the Dermatology and Cosmetic Surgery Center in Charlotte. "They're unprotected for those first 30 minutes" while the sunscreen is reacting with skin to create protection.

Apply sunscreen in a thick, even layer. "Most people don't apply enough sunscreen, which can turn your SPF 30 into a 20 or a 15," Rostan cautions.

This is cache, read story here