You either love it (too much) or hate it. Whether you're slathering your face in thick, rich creams post-wash, or reveling in the tight, clean feeling of cleansed skin sans moisturizer, both can damage your skin.

Because oily skin is notorious for causing pimples and blackheads, people tend to dry it out with acne medications and forego moisturizer, says Dr. Peredo. But shying away from moisturizer because you think it will make your skin oilier is ... wrong. Dry skin will overproduce sebum (pore-clogging oil) to compensate for the loss of moisture.

And those of you with dry skin might be tempted to slather on moisturizer; if some is good, more is better, right? But your skin can only absorb so much product. If you overdo it, the excess moisturizer can can your pores.

The fix: "Moisturizing regularly when you have oily skin helps to control the overproduction of sebum," Dr. Peredo says. If you have oily skin, use a toner to restore your skin's pH balance and zap dead skin cells, then apply a lightweight moisturizer all over your face. Use it sparingly on the oiliest parts of your face.

And if your dry skin feels too parched, Dr. Peredo recommends switching to a heavier, more emollient moisturizer at night rather than loading up on your regular moisturizer. If you find that heavier night creams cause your skin to break out, layer a gentle moisturizer (without SPF) over a face oil for extra moisture that won't clog your pores.