"Be careful with salt and alcohol volume," Gross says. "Salt collects in the skin and brings water, which in turn causes puffiness. Alcohol causes blood vessels to become leaky, so the water exits skin, causing puffiness in delicate spots, like the under eye area," he adds.

"Use sunscreen. It is something that is key and something I use religiously," Rodan says. Use products containing "zinc or avobenzone" (try Rodan + Fields Soothe UVA/UVB SPF 15 Sunscreen, $36). "You need to make sure they are the called out ingredients in the active ingredient list or you're probably doing your skin more damage," she says. "People have a false sense of security with sunscreens. You need things that won't let UVA light get through or you will accumulate more UV damage. This explains why the rate of skin cancer and aging has continued and progressed even though we're wearing more sunscreen than before," Rodan says.

The age-fighting ingredients most important to Wechsler are "prescription topical retinoids, such as Tretinoin (Renova, Retin-a), the gold standard in anti-aging. [They] treat surface fine lines and wrinkles, brown spots, thicken skin, prevent basal and squamous cell skin cancers," she says. "I use the lowest strength, but can't use it every day because of my very sensitive skin."

"You really have to practice safe sun," Fields says. "The hat I wear has a large round brim with a tail at the end. Not cute, but it really works. A baseball hat is pretty useless. It only covers the forehead and your nose. Safari hats found at sports stores are a better bet," she says.

"Eat water, don't drink it," Murad says. "The idea of drinking eight glasses of water is a fallacy, the water doesn't stay where we need it to stay," he says. Instead of drinking more water, which Murad says will just send us to the restroom more often, he recommends eating plenty of raw fruits (three or more servings a day) and veggies (five or more servings a day), which will also provide essential anti-oxidants and anti-inflammatory properties.