5. Use the Wrong Cleanser
A big mistake people make when they wash their face is using a harsh soap that's meant for their body. Keep the bar soap in the shower. Use only a mild cleanser for your face, especially if you have sensitive skin, Stein says.
If your skin is acne-prone, make sure the cleanser you use is oil-free and non-comedogenic. People whose skin is on the dry side should follow up each wash by applying a layer of lotion (preferably one that contains sunscreen) to seal in the skin's moisture.
6. Scrub Your Skin
Washing your face is a good idea. Scrubbing it isn't.
"Scrubbing can be very irritating to the skin," Stein says. "A lot of times, people who have acne will feel like they have to scrub the skin to make it better, but that can actually worsen the acne."
Be gentle to your skin. Wash your face using a soft, circular motion.
7. Pop Your Pimples
Control any sudden urge to pop a pimple. "Picking can actually make the acne worse and lead to permanent scarring," Stein says. "Better to leave it alone."
8. Stress Out
It's not your imagination. Stress really does show in your skin.
"It's not well understood, but it's clear that stress makes many skin conditions worse," Dover says.
Stress can cause flare ups of psoriasis and rosacea as well as acne. It may also lower the skin's ability to keep out harmful irritants and infections. Plus, people who are wrapped up in their stress have less time to care for their skin properly.
9. Overdo It
Looking young and vibrant is highly prized. But the quest for it can have a price, especially if you trust your chemical peel to someone without an MD after his or her name.
"I think they should be done under the guidance of a doctor because they certainly can be very irritating, particularly to sensitive skin or people who have skin conditions," Stein says. In the wrong hands, a chemical peel could leave you with an infection or permanent scars.
You also don't want to overdo home microdermabrasion and peels. Instead of making you look younger, they'll leave your skin red and irritated. Let your dermatologist guide you if you are going to try at-home skin procedures.
When you gain a lot of weight, your skin has to stretch to accommodate your new girth. Lose the weight and you'll be left with flabby, saggy skin. If your skin isn't elastic enough to bounce back, it can be incredibly difficult to tighten it up.