As you get older, wardrobe and style choices that worked when you were younger may no longer be serving you well. This goes for both men and women. Without knowing it, you may be looking older than you are. This could cause others to treat you as older and potentially hold you back from employment opportunities and advancements. This also can make you feel like you are not up to your game or comfortable in your skin. When you are not style confident, you are less body confident, which makes you feel less life confident.

Helpful: Seek out style mentors—people who look elegant and modern without chasing youth-oriented trends. Observe them carefully, and adapt elements of their style to your own. TV newscasters make good style mentors because they are required to look contemporary while also projecting dignity and authority.

Give yourself a good, hard look, and ask yourself whether you are looking older than your actual age with any of these common signals…

1. Sneakers for everyday wear. Your feet should be comfortable, but sneakers outside the gym just look sloppy and careless. Young people get away with it—but there are more stylish ­options when you’re older. These include loafers or driving moccasins for men and low-heeled pumps with cushioned soles for women. Wedge-soled shoes are a comfortable alternative to high heels.

2. Baggy pants. Although young men may look trendy in high-waisted, loose-fitting jeans, this style screams old on anyone else. For women, the rear end tends to flatten with age, causing pants to fit loosely in the rear. And front-pleated pants for women generally are unflattering and ­unstylish.

Better: Spend the time to find pants that fit well—or figure a tailor into your wardrobe budget. Baggy is dowdy, but overly tight makes you look heavier. Well-fitting clothes make you look slimmer and younger.

3. Boring colors. Skin tone gets duller with age, so the colors you wear should bring light to your face. If you are a woman who has worn black for years, it may be too harsh for you now. Brown makes men fade into the woodwork.

Better: Stand in front of a mirror, and experiment with colors that you never thought you could wear—you may be surprised at what flatters you. Avoid neon brights, which make older skin look sallow, but be open to the rest of the color spectrum. Try contemporary patterns and prints. For neutrals, gray and navy are softer alternatives to black for women, and any shade of blue is a good bet for men.

4. Boring glasses and jewelry. Men and women should have some fun with glasses. It’s a great way to update your look and make it more modern. Tell your optician what you’re looking for, or bring a stylish friend with you.

As for jewelry for women, wearing a large piece of fab faux jewelry (earrings, necklace, ring) or multiple bracelets adds great style and youth to your look.

5. Turtlenecks. You may think a ­turtleneck hides a sagging neck and chin, but it is more likely to draw attention to jowls.

Better: A cowl neckline for women, or a loosely draped scarf. A scarf is the single best item to help a woman look thinner, taller, prettier and more chic. For a video on how to tie a scarf, go to NYCityWoman.com and type “Six Ways to Wear a Scarf” in the search box. For a man, an oblong scarf, looped, is a stylish European look that adds a welcome shot of color.

6. Stiff or one-tone hair. An overly styled helmet of hair looks old-­fashioned. Hair that’s a solid block of color looks unnatural and harsh.

Better: Whether hair is short or ­shoulder-length, women need layers around the face for softness. As for color, opt for subtle highlights in front and a slightly darker tone toward the back.

Keep in mind that gray hair can be beautiful, modern and sexy. You need a plan to go gray, though, which means a flattering cut and using hair products that enhance the gray. Ask your stylist for recommendations. Also, if your hair is a dull gray, consider getting silver highlights around your face to bring light and “energy” to your hair.

Men who dye their hair should allow a bit of gray at the temples—it looks more natural than monochrome hair. But avoid a comb-over or a toupee. A man who attempts to hide a receding hairline isn’t fooling anyone—he just looks insecure.

Better: Treat your thinning hair as a badge of honor. Either keep it neatly trimmed or shave your head.

7. Missing (or bushy) eyebrows. Women’s eyebrows tend to disappear with age. Men’s are more likely to grow wild.

Better: Women should use eyebrow pencil, powder or both to fill in ­fading brows. Visit a high-end cosmetics ­counter, and ask the stylist to show you how. You may need to try several products to find out what works best. Men, make sure that your barber or hair stylist trims your eyebrows regularly.

Also: Women tend not to notice increased facial hair (especially stray hairs) on the chin and upper lip—a result of hormonal change. Pluck!

8. Deeply tanned skin. Baby boomers grew up actively developing suntans using baby oil and sun reflectors. Now pale is the norm. A dark tan not only dates you, it increases your risk for skin cancer and worsens wrinkling.­

Better: Wear a hat and sunscreen to shield your skin from sun damage.

9. Less-than-white teeth. Yellowing teeth add decades to your appearance. Everyone’s teeth get yellower with age, but with so many teeth-whitening products available, there is no excuse to live with off-color teeth.

Better: Ask your dentist which whitening technique he/she recommends based on the condition of your teeth—over-the-counter whitening strips, bleaching in the dentist’s office or a custom bleaching kit you can use at home.

10. Women: Nude or beige hose. Nude stockings on women look hopelessly out-of-date. Bare legs are the norm now for young women, but they are not a good option for older women who have dark veins.

Better: In winter, wear dark stockings or opaque tights. In summer, use spray-on tanner for a light tan…or wear nude fishnet stockings or slacks or capris.

11. Poor-fitting bra. Get a bra that fits. Most women don’t know that bra size changes as your body does. Giving your breasts a lift will make you look younger and trimmer.

12. Excess makeup. Thick foundation, heavy eyeliner, bright blusher and red lipstick all add years to your face.

Better: Use a moisturizing (not matte) foundation, and dab it only where ­needed to even out skin tone. To add color to cheeks, use a small amount of tinted moisturizer, bronzer or cream blush. Use liquid eyeliner in soft shades such as deep blue or brown, and blend it well. For lips, choose soft pinks and mauves, depending on your skin tone.

Bottom line: The idea is to have fun putting yourself together. That inner spark and personal style will show that you are getting better with age.