O Magazine ran an article featuring interviews with several top skin care experts and dermatologists (check it out here). Every single one of them said sunscreen was the most important part of your skincare regimen. It was the secret they would pass on to their daughters.

The number-1 cause of wrinkles is sun damage, so it's important to use sunscreen from your early years on even in winter and on cloudy days. A great trick is to purchase two moisturizers: One for night and one for day that includes UV protection. Don't use moisturizers with sunscreen at night, the ingredients are not meant to be used 27/7 and can aggravate skin. When choosing a sunscreen, make sure it contains Mexoryl (found in my favorite sunscreen La-Roche Posay) or Helioplex, found in Neutrogena products.