What are the most common tells of a woman's age? Most skin care regimens zero in on public enemy No. 1: wrinkles. But don't overlook other common skin conditions that magnify the years on your face. A range of issues, from subtle changes in your skin tone to chronic dryness, can make your skin look older.

We enlisted the help of Beverly Hills-based Dr. Ava Shamban, the expert dermatologist from "Extreme Makeover" and author of "Heal Your Skin," to identify the signs of aging and devise a plan of action to reverse them. Shamban says it's important to keep an eye out for specific "it" ingredients to combat problem areas and to implement lifestyle changes for lasting results.

Click ahead to identify the most common signs of aging and learn the best ways to start reversing them today.

While typically associated with lack of sleep, dark circles under the eyes are actually caused by the loss of fat around the eye, a common side effect of aging. When you're young, fat is distributed evenly around your forehead, temples, cheeks and around the eyes. But as you age, that fat loses volume and shifts down, and your skin sinks deeper into the pockets around your eyes. Failing to clock in enough beauty sleep only makes this reality more visible and apparent, but there are other lifestyle culprits exacerbating the problem.

According to Shamban, diets rich in sodium and a cigarette habit can contribute to dark circles. Salt intake dehydrates your skin, as does smoking, causing water retention and blood vessel dilation underneath the thin skin surrounding your eyes. To minimize dark circles, reduce your salt intake, ditch the cigarettes and schedule tea time. The caffeine in tea bags helps constrict dilated blood vessels. "Wet a tea bag with hot water, let it cool and apply to the under-eye area for 15 minutes," Shamban advises.

When it comes to your skin care routine, focus on under-eye products rich in peptides. Retinol can be too harsh around the delicate eye area, so peptides are a good solution for more sensitive skin types. Regular use can reduce the appearance of dark circles and other telltale signs of aging like wrinkles and fine lines.

Here's the dirty little secret about wrinkles: There are several factors that contribute to their formation beyond the number of birthdays you've had. To pick the best way to battle unwanted wrinkles, it's important to know why they've formed in the first place. According to Shamban, there are several types of wrinkles, all of which involve the degradation of connective tissue (collagen and elastin) due to aging or UV exposure. These aren't scientific categories; rather, they're grouped by treatment.

The Culprits:
•Facial expressions: Crow's feet, forehead lines and other fine lines around the eyes and nose come from facial movement and can be treated with Botox.
•Fat loss: Tissue degeneration and fat loss cause naso-labial folds (the parentheses-shaped lines that extend from the bottom of the nose down to the chin) and marionette lines (the lines running downward from the chin). Both can be treated with fillers.
•Fine lines: Also known as lines of laxity, fine lines can be treated with lasers, radio frequency and ultrasound at the derm's office, or with exfoliating topicals like retinols and alpha hydroxy acids at home.
•Dehydration: Extreme dryness can create fine lines that can be treated topically with at-home moisturizers.

If you have a combination of these issues, the best thing you can do is follow an antioxidant-rich diet and get plenty of sleep to repair and promote faster cell regeneration. Click ahead to read more about the ingredients, products and practices you can add to your routine to amp up the effectiveness of your anti-aging skin care arsenal.

Look for a single product that targets multiple signs of aging, such as a creme that promotes cell turnover, to make your skin smoother, softer and more radiant over time. According to Shamban, one of the most significant tools at your disposal is sunscreen, which you should use every day, regardless of weather. "If there's enough light to read by, there's enough UV floating around that you should protect yourself," she says. "And if you live in a particularly warm or sunny area, you must reapply at midday."

"Remember that it takes at least three months in some cases and six months in others to really see the results of any skin care regimen, so don't give up," Shamban reassures.

Hyperpigmentation, a skin condition in which patches of skin become darker in color, is caused by an excess production of melanin. According to Shamban, a variety of factors spark this excess of melanin, including hormones, medication and, most commonly, UVA rays from the sun, which cause age spots.

Age or liver spots are exclusively caused by years of UV damage from unprotected sun exposure. "You see more of them on the left side of the face due to driving and on the hands because most of us rarely use sunscreens on our hands," Shamban explains.

Luckily, hyperpigmentation can be treated with topical products, but the No. 1 priority is to minimize sun damage in the first place. "Once and for all, lay to rest the myth that 'healthy tanning' exists. Tanning is a sign that the body has been injured," Shamban says. She stresses the importance of daily, thorough and reapplied sun protection not only on the face, but also on the chest and hands. At the end of the day, your No. 1 prescription is "sunscreen, sunscreen and more sunscreen," Shamban says.

As you age, your skin gradually loses more and more collagen, the protein that aids your skin's elasticity. But the truth is, skin sagging can happen at any age due to lack of exercise, sun damage, dehydration and even weight loss, so it's important to think defensive strategies in your skin care regimen and lifestyle. According to Shamban, the best at-home treatments are rich in vitamin C and alpha or beta hydroxy acids, which stimulate collagen production.

Beyond your beauty routine, it's doctor's orders per usual: Exercise regularly, drink plenty of water throughout the day and sleep regularly to promote collagen production. Complement your fitness routine with anything that increases muscle tone -- exercises as simple as these face yoga poses can help promote a more youthful appearance.