Yes, yes, sunscreen; you've heard this a million times. But here are the most important sunscreen tips to remember: Use a physical sunscreen (aka, one whose key ingredient is zinc or titanium dioxide) and choose one that's SPF 30 or higher.
Physical, as opposed to chemical, sunscreens provide a shield reflecting the sun's rays and preventing UV penetration. Studies show that traditional white zinc oxide (as opposed to nanoparticles of zinc) continues to be the absolute safest and most effective sunscreen ingredient, defending against UVA and UVB rays, says Elina Fedotova, celebrity esthetician, cosmetic chemist, and founder of Elina Organics. They don't absorb into the skin quite as well as the chemical or nano stuff, but ultimately, they are just better all around. Not to mention, zinc oxide is anti-inflammatory and can soothe irritated skin while protecting it even further.
You'll also want to choose an SPF of level 30 or higher—though SPF 30 is about as protective as you can realistically get. "SPF 30 has a 97% protection rate," explains celebrity esthetician Danné Montague-King, founder of DMK skincare. "Going higher in count (e.g., 50 to 60) will give you a bit more: 98% protection."