Memorial Day weekend marked the unofficial start of summer and I know a lot of people celebrated by hitting the beach. I love the surf and sand as much as the next girl, but if there's one thing I'm a stickler about, it's sunscreen -- I don't go anywhere near the beach without my SPF.

As a very pale and freckly Irish girl, I'm always slathering on the highest sunscreen I can find to protect my sensitive skin from burning. Needless to say, when I saw that Neutrogena had launched an SPF 100, I was really excited.

Now I know what some of you are thinking: that's just excessive. It's true that higher sunscreen doesn't always mean the best protection. To ensure you get the best possible protection, look for sunscreens that shield against both UVB (burning) and UVA (aging) rays.

While SPF 30 is fine, my motto is better safe than sorry. If I'm going through the trouble of slathering on the sunscreen, I want to know that what I'm putting on is the highest protection that I can get.

But perhaps the biggest factor in protecting yourself from damaging rays is to be sure you are applying enough sunscreen. According to Yohini Appa, the Senior Director of Scientific Affairs at Johnson & Johnson, "If you apply half the dermatologist-recommended one ounce of sunscreen you get the protection of only the square root of the SPF. So by applying only a half-ounce of SPF 70, you actually only get an SPF 8.4."

So no matter what your starting SPF is, make sure you're putting enough of it on. The rule of thumb is apply one ounce, or a shot glass full, of sunscreen. And, most importantly, don't forget to reapply every few hours.

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