11 Major Mistakes Beauty Experts Wish You'd Get a Clue About

When your hair spray can reads "apply eight inches from the head," you should listen! Backstage at Marchesa, lead hairstylist Antonio Corral Calero revealed women are committing two major aerosol sins: too much and too close.

"When we think of hair spray, we think '80s crunchy, very coated," he said. "But the formulas today have technology that make the hair stay without feeling it." So keep your spritz at arm's length, please.

The dewy look is all the rage, and women everywhere are trading in their caked-on coverage for a sexy, natural glow. But backstage at Reem Acra, lead makeup artist Mark Carrasquillo revealed the biggest mistake you're making with your shine: putting it everywhere.

"If you want shine, you really have to decide where you're putting it," Mark stressed. "Make sure you keep around the nose and under the eyes matte. Otherwise, it'll make you look beat up and tired. I always think of that drunk girl at the party that shines in the wrong places."

To avoid being that girl, focus highlighter on your cheekbones, forehead, and nose. But careful — you want to avoid the ball of your nose because too much glimmer can make it look rounder and bulky. Instead, center the product on the bridge to slim and elongate.

Rebecca Isa, the lead manicurist for Zoya at the Marchesa show, has one pet peeve when it comes to nails: filing. "Going back and forth tears the nail plate," Rebecca explained. "It should be corner to center in one direction."

If you see your nail tech starting to saw, stop her right away! Once the emery board is put away, make sure she buffs the free edge, too. Otherwise you'll have flyaways that will cause your polish to chip in a matter of days.

Pumpkin should be saved for Halloween . . . When we asked Polly Osmond, the head makeup pro for Christian Siriano, what women need to stop doing, she replied, "Orange faces!"

She went on, "I have a feeling that the people who wear orange foundation actually like wearing orange foundation. I see it a lot on air stewardesses — I am not trying to single them out, but that's when I notice it. You can see it on the neck, and I just want to rub it in."

To find the right foundation shade for you, she recommended looking at it in natural light.

We've all experienced this beauty struggle: after working hard to grow out your nails, one suddenly snaps off. While you'll be tempted to keep the rest of your nails long as the stub grows out, just don't. "Just cut them all," said Michelle Saunders, the lead Essie manicurist at Diane von Furstenberg. "It never looks as elegant as you think it does!"

Just because you broke up with your spouse or got laid off from your job doesn't mean you should get a pixie cut or dye your hair fire-engine red. Odile Gilbert, the lead stylist for Kérastase at Thakoon, advises you to stay away from the salon when you're feeling vulnerable.

"You have some moments in your life when you are unhappy, and you should not make a hair change then," she said. "Sometimes it's better to go shopping. Buy yourself something if you don’t feel good, rather than cutting off all of your hair. Go buy yourself a piece of jewelry or flowers or shoes — anything!"

Our advice: wait at least two months after the life event happened, and if you still want to make a hair change, then go for it. Or pull a Lauren Conrad, and cut your hair in stages like she did here when she got a lob.

Diane Kendall, the lead makeup artist for NARS at the Thakoon show, would like you to please not overapply makeup colors.

"They put too much product on brushes, and then when they go to apply it, it looks too heavy," she explained of those who are heavy-handed. "Always tap it to get any excess powder off."

Easy enough! Just don't forget this important step to avoid doll cheeks.

Yes, they're incredibly convenient, but gel manicures just aren't worth it. Sunshine Outing, the lead manicurist for Zoya at Rachel Zoe, said that these long-wearing paint jobs are great for her celebrity clients, but she doesn't recommend them to anyone else.

"I get it — it's important to wear what's best for your lifestyle," she said, "but gels are so damaging." She recommended reapplying topcoat to a fresh manicure every other day to keep it glossy and chip-free. "It can last two weeks if you take good care of it!"