The trick: Whiten your teeth.

Why: An annoying sign of aging: In addition to the yellowing that naturally happens by eating dark food and drink, teeth get more dull-looking as they wear and your tooth enamel thins. That's why having whiter teeth is shown to make people look five years younger, among a host of other benefits. (It makes you more employable!)

Try: There are so many teeth-whitening products on the market that it's possible to sport a smile that's several shades whiter within days. Look for tooth-whitening products with a concentration of 10 to 15 percent peroxide to avoid compromising your teeth's enamel; try GoSmile Speed Whitening System.

If you gnash your teeth at night, take steps to avoid wear and tear: Stay away from hard or chewy foods (gum, taffy, tough vegetables like raw carrots, etc.) that exacerbate grinding and/or use a mouth guard at night.

The trick: Stand up straight.

Why: This schoolmarm-y advice has a purpose. Not surprisingly, studies show that poor posture makes others perceive you as older and heavier than you really are. Standing up straighter elongates the body, making you look thinner, a hallmark of youth.

Not only does slouching make you look older, it actually ages your body: Poor posture is associated with a higher risk of cardiovascular disease and other chronic health problems.

Try: Analyze your environment, routine and habits for factors that might be reinforcing your slouching habit. Do you have a crappy desk chair with no back support? Are you prone to shopping online while slumped over on your couch? Is your car's rearview mirror pointed too low, or do you lean forward in your car seat when traffic makes you tense? Tweak those detrimental habits now.

In the long-term, do core-strengthening exercises to support good posture. Crunches, planks, scissor kicks, burpees -- get creative.

The trick: Trade your glasses for contact lenses.

Why: Just in case you were wondering, those thick-framed hipster specs aren't doing you any favors. Like, any.

Research indicates that glasses make people look an average of three years older. What's worse: The older you are, the older they make you look. Subjects older than 45 were judged as five years older than their true age when they wore specs. Ouch.

Try: Contacts aren't for everyone, but new developments in technology are making them easier to wear. Hate taking out your lenses before bed? Products like AirOptix Night & Day Aqua are approved for extended wear for 30 days. Can't be bothered to care for them? Buy daily disposables like 1-Day Acuvue.

Whatever lens type you choose, practice good hygiene: The Centers for Disease Control and Prevention recently released numbers indicating that eye infections from contact lenses are responsible for 1 million doctor appointments and ER visits every year.

The trick: Even out your skin tone.

Why: Many women bemoan their wrinkles as the reason they look older, but science says skin tone has more to do with youth (or lack thereof).

Experts say the main reason people are judged as older is not because of wrinkles but because their skin tone is not uniform-looking. Hyperpigmentation from sun damage or hormones is usually the culprit. And it's not just your face: uneven tone on the neck and chest are also dead giveaways of age.

Try: There are tons of foundation, powder and concealer products for making the skin on your face look more even. Now there are also products geared toward making the skin on your body look more uniform via pigments and light-reflecting particles. The new body BB creams use sheer pigments and light-reflecting materials to create the illusion of more even skin. (We love Urban Decay Naked Skin Body Beauty Balm.)

Any self-tanner can help skin look more uniform, and you can't go wrong with gradual formulas like Jergens Natural Glow Daily Moisturizer.

Also great: "Express" tanning formulas that develop over a few hours and can be washed off once you achieve your desired darkness. We like Vita Liberata Rapid Tan Mousse.

The trick: Use volume-boosting hair products and tools.

Why: There's a reason you've probably never seen an elderly woman with a thick, flowing head of silvery hair. Scientists have researched the thickness of hair in women of all ages and found that there's a measurable difference in the thickness of strands between young, middle-aged and elderly women. So even if you don't experience gradual hair loss (knock on wood), your strands literally thin with age.

Try: If you've ever been disappointed by volumizing products in the past, take heart: Recent advances in technology have led to products that are clinically proven to plump each strand from the inside, literally thickening its diameter with continuous use. Pantene Expert Collection Age Defy and L'Oréal Paris Volume Filler are two product lines that utilize these technologies.

In the meantime, fake thick hair until you make it. "Dry" sprays -- dry shampoo, dry finishing spray and dry texturizing spray -- are capable of http://www.totalbeauty.com/reviews/product/6561612/batiste-dry-shampoo the finest-haired ladies bodacious-looking body instantly. (We like Batiste Dry Shampoo, Redken Wind Blown 05 Dry Finishing Spray and Shu Uemura Art of Hair Dry Texture Wave.)

If you have mid-length to long hair, styling hair in loose waves goes a long way in creating the illusion of thickness. Just look at celebs like Jennifer Lopez and Julia Roberts, forty-somethings whose luxuriant waves make them look so much younger. Try an easy-to-use automatic wand like the Kiss InstaWave.