Washing your face at night goes beyond taking off your makeup. You're also removing dirt and particulate pollution from your face. And new research shows that this pollution contributes to wrinkles and brown spots -- possibly as much as sun exposure. And pollution has been linked to skin conditions like eczema and psoriasis, as well. For the healthiest skin possible, wash your face every night -- no lazy girl excuses.

Just because you're layering on a serum and moisturizer every morning and night, doesn't mean the serum and moisturizer are doing much to improve your complexion. And if the active ingredients like antioxidants and peptides are sitting on top of your skin without sinking in, you're essentially wasting the money you spent on those products. In order to maximize the benefits of your skin care, you need a healthy skin barrier (the outermost layer) -- because when your surface layer is functioning well, it allows skin-enhancing ingredients to penetrate more easily.

Using a product like Elizabeth Arden's SUPERSTART Skin Renewal Booster, $65, helps skin's ability to repair and renew while allowing your serum and moisturizer to work harder. It's packed with botanicals and probiotics for optimal skin health.

"By incorporating a product like SUPERSTART into your regimen, you are helping the skin function at its highest potential, and by doing so maximizing the results of all products you have been using," says Engelman.

You've heard it a million times, but let's make it a million and one for good measure: You need to wear sunscreen daily. Not just in the summer. Not just when you're going to the beach. And not just in your makeup (unless you're slathering on a teaspoon of the stuff). You need to wear a sunscreen with at least an SPF 30, and you should apply it every morning for the healthiest skin possible.

An Australian study of 900 men and women found that people who used sunscreen religiously for four and a half years showed no signs of skin aging. We repeat: They did not age. So stop hunting for that fountain of youth, and spend your time shopping for a sunscreen that you like instead.

Here's the problem with thin skin: It generally lacks some (or all) oil glands, which means it dries out quickly, and the barrier is easily compromised. "Pay special attention to eyes, neck and décolleté," says Engelman. "That skin is thinner and tends to be the first to show signs of aging."

And wrinkles on your chest or the backs of your hands will give away your age -- even if you've worked hard to keep your facial skin looking as young as possible. For amazing looking skin from head to toe, use your facial skin care routine anywhere that's exposed -- i.e. your neck, chest and hands -- and pay special attention to the delicate skin around your eyes.

Here's what scientists know for sure: What you put in your mouth will affect the way your skin looks and functions. Some myths are just that: myths. If you eat a French fry or a piece of chocolate, for example, you're probably not going to break out. But recent studies have uncovered a clear link between dairy and acne. And that same research applies to high glycemic foods in general -- so cake and cookies are equally dangerous to a clear complexion.

Fortunately, there are also skin-benefitting foods. Tomatoes, for example, are rich in lycopene, which boosts the skin's ability to protect itself from the sun. And foods loaded with omega fatty acids, like salmon and nuts, keep skin naturally moisturized and help maintain good barrier function. Meanwhile, antioxidant-rich foods like blueberries help the skin block damage-causing free radicals.

Many doctors say they can assess a patient's diet purely by looking at their skin. And the healthier you eat, the better your skin will look.