1.Wash at night

"The most important time to clean your face is before you go to bed," says Prevention's dermatologist Dr Stephen Shumack of Sydney's Royal North Shore Hospital. Waking up on a grubby pillow isn't hygienic, and wearing make-up overnight can irritate your skin, clog pores and trigger breakouts. Before retiring, use a gentle face wash (skin should feel pleasantly tight after cleansing), which also allows anti-ageing creams to penetrate deeper for better results. Once a day is enough—oil production decreases with hormonal changes in your 40s, and overcleansing can dry out your complexion and make wrinkles look more pronounced. To refresh skin in the morning, splash with lukewarm water.

2. Be vigilant about UV protection

Nothing is more important than sun protection; ideally, if you want to preserve younger-looking skin, wear a hat and SPF 30+ when in the sun. Why? While we need 10 minutes of sun exposure a few times a week to ensure our supply of vitamin D, any more than that can rapidly lead to wrinkles and sunspots. If your moisturiser isn’t formulated with SPF 30+, add a broad-spectrum sunscreen to your regimen daily.

3. Manage stress

You can't always avoid it, but you can change the way you deal with it. Emotional upheavals can make your skin look 5 years older, says dermatologist and psychiatrist Dr Amy Wechsler, author of The Mind–Beauty Connection: 9 Days to Reverse Stress Aging and Reveal More Youthful, Beautiful Skin ($26.99; Simon & Schuster, available 1 December). Constant anxiety causes your body to increase production of the stress hormone cortisol, which results in inflammation, which in turn breaks down collagen. To help counteract the effects of inflammation, eat foods rich in antioxidants, such as berries, oranges and asparagus.

4. Use a retinoid

Research shows that these vitamin-A derivatives speed cell turnover and collagen growth to smooth fine lines and wrinkles and fade brown spots. Prescription-strength retinoids, such as Retin-A, provide the fastest results—you'll start to see changes in about a month. However, retinoids are also quite potent, so when you start using them, apply just a pea-sized drop to your face every third night, then build up to nightly usage. Many cosmetics contain retinol as an active ingredient in concentrations that aren't as harsh as those in prescription formulas. Try L’Oréal Paris Revitalift Face, Contours & Neck ($35.95; chemists), RoC Retin-Ox Intensive Anti-Wrinkle Moisturiser Day SPF 15 ($49; selected chemists) and Skeyndor Pure Retinol Night Cream ($133; selected spas and salons).

5. Update your skincare routine

Changing even one product in your palette every 6 to 12 months jump-starts more impressive improvements in tone and texture. "When you apply products consistently, your skin slides into maintenance mode after about a year," says dermatologist Dr Mary P Lupo. To keep skin primed for rejuvenation, substitute a cream that contains alpha hydroxy acids for your prescription retinoid twice a week.

6. Eat omega-3s

These 'good' fats in foods such as salmon, flaxseed and almonds boost hydration, which keeps your skin supple and firm. The same isn't true of the saturated fats in dairy products and meats, which increase the free-radical damage that makes your skin more susceptible to ageing. Try to keep your saturated fat intake to around 17 g daily.

7. Exercise regularly

Studies find that women who regularly work out have firmer skin than women with comparable skin who don't exercise. The reason: exercise infuses skin with oxygen and nutrients needed for collagen production. To keep your skin toned (and with a healthy glow), make time for at least three 30-minute workouts per week.

More: See 30 Ways to Look Younger