Odds are on your good days, anyway—you feel younger than you look. (Have you ever caught a glimpse of yourself in a shop window and thought, "OMG, is that my mother?") The truth is, we're lucky to be getting older. But there's no reason it has to show.

The trick is to know the markers of youthfulness. Think of your favorite 5-year-old: "Big eyes, full lips and a luminous, unblemished complexion," says Robyn Gmyrek, MD, assistant clinical professor of dermatology at Columbia University Medical Center in New York City. Contrast is another sign, says Chicago plastic surgeon Steven Dayan, MD. Rosy cheeks and lips, clear eyes fringed with dark lashes—they all make a face appear brighter and more attractive, he says. Even your eyeballs—your eyeballs!—reflect your vitality. One study showed that a distinct limbal ring (the outline around the iris, which can disappear over time) is more appealing than none in identical faces.

If you're interested in looking as great as you feel, read on!

Dress, Milly, $775. Earrings, Paige Novick. Necklace and bracelet, Sarah Magid Jewelry.

A Gleam in Your Eye

Liner and mascara not only create contrast between the eyes and skin, but also help the eyes appear larger. "Trace an espresso brown or smoky gray pencil as close to the upper lash roots as possible to make the base of the lashes look denser," says L.A. makeup artist Pati Dubroff. Then use a volumizing mascara on the upper lashes to add lushness (try L'Oréal Paris Voluminous Miss Manga Rock Mascara). For the lower lashes, Dubroff prefers a thin formula, like Surratt Pointilliste Mascara. She lines the inner lower rims with a flesh-tone pencil (such as Chanel Le Crayon Khôl) to increase brightness.

Arch Support

To enhance brows, makeup artist Laura Geller, founder of Laura Geller Beauty, uses a dry pencil instead of a creamy one (get Marc Jacobs Beauty Brow Wow Defining Longwear Pencil) because it adheres better to skin: "Choose taupe—you can make it lighter or darker depending on how much pressure you apply," says Geller. Using short, fine strokes, fill in any sparse patches and then comb through with a spoolie brush.

Ring Tone

A fading limbal ring may seem beyond your cosmetic control, but even that can be cheated now: 1-Day Acuvue Define contacts mimic the appearance of a sharp limbal ring without changing the color of the iris. (They're also available without vision correction.)

Finishing Touch

Mask complexion concerns with either a tinted moisturizer, like Olay Total Effects Pore Minimizing CC Cream, or a heavier full-coverage foundation, such as Laura Geller Baked Liquid Radiance Foundation. Whatever you choose, "if your goal is to appear youthful, it's really important to stay away from powders," says Dubroff. "You want skin to have a dewy finish." Begin by applying a liquid or a cream with a brush in the center of your face (under the eyes and around the sides of the nose and mouth). "That's usually where the color is most uneven," she says. Work out toward the perimeter with your brush. Go over any blemishes with a more opaque concealer (we like Maybelline New York Master Conceal by Face Studio), using a stippling motion with your fingertip, says Geller. To hide dark under-eye circles, Dubroff prefers concealers with built-in brushes (try Philosophy Hope for Everywhere) because they're easy to work with. "I start at the inner corner of the eye and go about a third of the way across beneath the lower lashes," she says. "Then I apply concealer at the outer corner and blend the two to meet, so I don't end up with a thick layer."

Cheek Chic

Mimic full, flushed cheeks by dabbing cream blush (Lancôme Blush Subtil Crème in Corail Alizé is good) directly on the apples. "The effect is like you've pinched that area to bring the blood flow back," Dubroff says. "If you have a warm or olive skin tone, stick to peach; if your skin is on the cool side, try a pink."

Smart Mouth

All you need for gorgeous lips is liner and tinted balm, according to Dubroff. "For both, choose a color two shades darker than your natural lip—a warm berry or a soft rose," she says. Avoid orange tones, as they can emphasize any yellow in your teeth. Fill in lips with pencil (such as Elizabeth Arden Beautiful Color Smooth Line Lip Pencil), and then coat with tinted balm (like CoverGirl Jumbo Gloss Balm Sheers).

To keep your teeth as white as possible, limit your consumption of staining beverages, like red wine, tea, and cola, which penetrate the enamel, and eat fruits and veggies high in fiber, such as apples and raw carrots, which clean teeth's surface. An arresting smile requires more than just whitening, however. Over time, your teeth may become shorter from chewing and grinding, says New York City cosmetic dentist Marc Lowenberg, DDS. If you notice you're grinding, speak to your dentist, who may suggest wearing a night guard.

A fact of life for all women: As we age, our bone mass inevitably decreases, says Sabrina Strickland, MD, associate professor of clinical orthopedic surgery at Weill Cornell Medical College in New York City. "The spine becomes compressed, and we lose height," she says. And if we're prone to osteoporosis, we're more likely to develop that very unyouthful hunch.

Stand Tall

One of the most effective ways to maintain strong bones: weight-bearing exercises, like squats, weight-lifting, and jogging, says Strickland. Equally important: strengthening your core muscles through activities such as Pilates and yoga, which can improve posture and balance.

Poor posture can worsen spinal compression, says New York City chiropractor Karen Erickson. The next time you find yourself slouching, try this (or try it right now): Stand up straight with your shoulders pulled back and your stomach tucked in. Avoid tilting your head forward or backward, keep your knees slightly bent and balance your weight equally on both feet. Feel the difference? Looking good!

Swimsuit, Vince Camuto, $106. Bracelet, Miansai.

Even before the days of Lady Godiva, lustrous hair was linked to good health, fertility and femininity. But, according to Chicago plastic surgeon Steven Dayan, MD, "at least 40 percent of women over age 40 start to have hair loss." For these women, "the goal is to restore the universal indicators of beauty: shine, smoothness, luminosity and volume," says New York City dermatologist David Colbert, MD. Silver foxes will be glad to know that haircolor is less important when it comes to communicating vitality.

Pleasantly Plump

Help for thin strands starts in the shower with a thickening shampoo and conditioner, like Dove Oxygen Moisture Shampoo and Conditioner. Next, while hair is wet, add a volumizing spray (try Garnier Fructis Full & Plush Mega Full Thickening Lotion) or mousse (such as Redken Stay High 18 High-Hold Gel to Mousse) from roots to ends, says Lona Vigi, Nexxus New York Salon Care celebrity stylist. Then blow-dry your hair away from your face to give it swing. "Movement is really important. It makes your hair look full and stylish," Vigi says. Need more help? Coloring your hair increases the diameter of the hair shaft. If you're thin on top, zigzagging your part is another way to give the illusion of more hair. Partial wigs and clip-in extensions can also create fullness (try Euronext Premium Remy 18-Inch Clip-In Extensions).

Sparkle and Shine

Avoid overshampooing and excessive blow-drying, which strip the hair shaft, making it appear dull and ragged. You can also try a weekly deep conditioner (Nexxus New York Salon Care Emergencée Reconstructive Treatment is a good one) to help replenish lost moisture and stave off breakage, says Vigi. On dry hair, apply a shine spray (we like Herbal Essences Wild Naturals Illuminating Dry Oil Spray) "just from the midshaft to the ends."

To Dye For

If you decide to color your hair, "it's key to mix in highlights a couple of shades lighter to give it dimension," Vigi says. "One solid shade can look like a helmet." Are you more of a natural woman? Completely silver hair looks gorgeous when the cut is modern and bouncy.

Swimsuit, Melissa Odabash, $258. Earrings, Giles & Brother. Necklace, Tory Burch.

Hair: Domingo Quintero for Serge Normant at John Frieda Salon/Jed Root Inc. Makeup: Christina Reyna for Sephora Pro Collection at Ray Brown Represents. Manicure: Roseann Singleton at Art Department using Dior Vernis. Set design: Lisa Gwilliam for Jed Root Inc.