Sometimes skin seems like nothing but trouble. Between dry and flaky skin, oiliness, and acne-prone patches, you might feel like there's a daily battle between you and your skin. You attack with soaps, cleansers, toners and moisturizers, but your skin just counterattacks with itchiness, pimples and inflammation.

Truthfully, however, your skin is your friend. It's a barrier between your body and the outside world, protecting you from microorganisms and pollutants in your environment. Part of this protection is an oil produced by your skin called sebum. It keeps bad stuff out and holds good stuff (like moisture) in. It's a good oil, but it can cause skin problems when it's produced in excess. When you wash your face, you want to get rid of dirt, dead skin cells, makeup, pollutants or microorganisms and excess sebum -- but you need to maintain a protective layer of oil.

Although basic cleansing principles apply for all types of skin, problem skin presents some unique challenges. People with oily skin need to focus on removing the dirt and grime while refraining from any extreme measures that will strip oil from the skin and leave it unprotected. People with dry skin have to choose products that won't further dry their skin but will replenish moisture without clogging pores or causing irritation. And when skin is inflamed because of allergies, chemical irritants, eczema or other conditions, you have to take special care to avoid irritation.

For tips and techniques on forging a peace treaty with your skin, read on.