As Alanis said, “It’s the good adviiiiice that you just didn’t take.” Er, in this case, the good advice that you just didn’t know years ago. It happens. New research comes out over the years and experts realize how much of a difference certain habits or behaviors really make when it comes to how you look and feel. Here, to save you from making any beauty-harming mistakes, 10 pros share how they’d change their 20-something habits if they could go back in time—and offer current solutions that work.

Hey, Self: “Cut back on the sweets!

Hey, Self: “Cut back on the sweets!”

Why: Glycation—the process that happens when you have excess sugar molecules floating around in your body—stiffens the collagen and elastic fibers in the skin and ages you with wrinkles.

Now, I…Eat lots of sweet fresh fruit, like strawberries, melon, cherries, peaches, nectarines, blueberries and apricots. Fruit has a lot of natural sugar, but it also contains fiber and antioxidants. I still treat myself on occasion to my favorite treats like gelato or a pastry, but in moderation. —Debra Jaliman, M.D., assistant professor of dermatology at Mount Sinai School of Medicine in NYC and author of “Skin Rules

Hey, Self: “Don’t pick at your blemishes!

Hey, Self: “Don’t pick at your blemishes!”

Why: The “stuff” that comes out actually goes deeper into the skin, causing even more inflammation and scarring.

Now, I…Put a dab of retinol or benzoyl peroxide on a zit. And if possible, I just leave it alone (but that’s hard to do). —Sandy Johnson, M.D., dermatologist at Johnson Dermatology in Fort Smith, Arkansas

Hey, Self: “Put sunscreen on your hands and arms—every day!”

Why: Applying SPF to more than just your face is important. It makes a huge difference in terms of photoaging (fine lines, wrinkles, and sun freckles). There’s no question that aggressive protection early on pays off later—for both prevention of aging and skin cancer.

Now, I…Use sunscreen daily on my face, hands, arms, and upper chest to prevent further sun damage. This is really easy to do now with the variety of light, non-greasy over-the-counter sunscreens available. —Susan Swetter, M.D., dermatologist and director of the Pigmented Lesion & Melanoma Program at Stanford University Medical Center & Cancer Institute

Hey, Self: “Figure out how to love fish!”

Hey, Self: “Figure out how to love fish!”

Why: These sea creatures are packed with anti-inflammatory omega-3s, which help to prevent cellular breakdown and add moisture to the skin.

Now, I…Take omega-3 supplements and eat salmon and walnuts (also a great source) regularly. —Carolyn Jacob, M.D., F.A.A.D., dermatologist and director of Chicago Cosmetic Surgery and Dermatology

Hey, Self: “It’s OK to wear foundation!”

Why: Foundation is basically moisturizer with color pigments, so it provides protection against the elements. (Well-moisturized skin makes a better barrier from sun and wind.) And if the moisturizer has SPF, that’s an added bonus as it will double the protection.

Now, I…Wear a foundation that matches my skintone every day to protect my freckly skin. But I use it sparingly so as not to look too “done up,” which was the main reason I skipped it in my younger years. —Fayne Frey, M.D., dermatologist in West Nyack, New York, and founder of FryFace

Hey, Self: “Simplify your routine!”

Hey, Self: “Simplify your routine!”

Why: You don’t need to spend a great deal of money on tons of products. In fact, using too many products can actually increase acne or result in allergic rashes.

Now, I… Find one or a few items, like a wash and a sunscreen, that work for my skin—and stick with them.  —Kristen M. Kelly, M.D., professor in the dermatology and surgery departments at University of California Irvine

Hey, Self: “There’s no such thing as a ‘base’ tan!”

Hey, Self: “There’s no such thing as a ‘base’ tan!”

Why: Research has shown that any UV exposure leads to cell and DNA damage, so you’re not doing yourself any favors by trying to get a ‘base’ before vacation. A good tan really doesn’t exist.

Now, I…Slather on SPF 30 or higher every day, no matter what. —Paradi Mirmirani, M.D., F.A.A.D., dermatologist at Kaiser Permanente

Hey, Self: “Go easy on the eyebrow plucking!”

Why: That hair takes a long time to re-grow and re-shape and you might not be able to get your thick brows back if you overdo it.

Now, I…Splurge for a professional trim or eyebrow shaping. It’s worth it for the best cosmetic outcome. —Tina S. Alster, M.D., director of the Washington Institute of Dermatologic Laser Surgery and clinical professor of dermatology at Georgetown University Hospital

Hey, Self: “Eat a Mediterranean Diet!”

Hey, Self: “Eat a Mediterranean Diet!”

Why: You’re born with certain-sized telomeres, which are the protective tips at the end of your chromosomes, sort of like the plastic tip of a shoelace. As you get older, telomeres get shorter until they’re no longer there. As telomeres die, you and your skin ages. One thing we know that actually helps slow that process is a Mediterranean diet.

Now, I…Eat less meat and more plants, plus lots of olive oil, avocados, nuts and fruit. —Janellen Smith, M.D., professor in the dermatology department, University of California Irvine School of Medicine

Hey, Self: “Stop scrubbing your face!”

Hey, Self: “Stop scrubbing your face!”

Why: Acne is not caused by dirt. If you try to over-scrub, you’re going to make acne and scarring worse.

Now, I… Avoid vigorous washing and harsh cleansers, such as those with nuts, seeds and abrasive materials. Plus, I always rub gently. —Diane Berson, M.D., F.A.A.D., associate clinical professor of dermatology at Weill Medical College of Cornell University