It isn't always your skin that shows the signs of aging. Dull, lackluster hair can be another dead giveaway to your age, and can make you appear older than you are. Keep your hair shiny, smooth and soft by using a nourishing hair mask, like Kerastase Masque Densite, $62, once a week.

If eyes are the windows to your soul, then your hands, neck and décolletage are the windows to exactly how old you are.

If you only apply your anti-aging serums and moisturizers to your face, that's (not shockingly) the only place you'll see the benefits. Why spend money on achieving a line-free face if your turkey neck is just going to give away your age? In addition to your face, smooth your serums and moisturizers down your neck, over your décolletage and even on your hands to keep everyone guessing your age. (Read more about how to keep your hands from giving away your age here.)

As you age, your metabolism starts to slow. Getting in at least 30 minutes a day of exercise can help boost your metabolism -- not to mention, studies have shown that doing weight-bearing activities, like walking and jogging, can help increase bone density.

In one year, the average commuter racks up nearly 200 hours of sun exposure -- just from driving. And, according to the New England Journal of Medicine, people who commute often age more quickly -- think, sun spots, fine lines and wrinkles -- on the left side of their face, which is exposed to more sunlight when driving. Whereas your windshield has an SPF of 50 or more, side and rear windows only have around 16.

To keep the sun out, load up on SPF every day (yes, even in winter), or tint your car windows. Not only will you look like a VIP driving around town, you'll block nearly 99% of harmful UV rays that can lead to premature aging and -- even scarier -- skin cancer.