Please read this. This is the single most important thing to learn about skin care.

All about your skin's barrier function.

The barrier function of the skin is what protects your skin from the environment and from water loss from the skin. To further break this down, your acid mantel is what protects your skin. Acid Mantel: A thin layer of sweat and oil on your skin. This is what keeps you waterproof. When this is stripped away you can create a whole host of problems. Most people strip the acid mantle when we wash with hot water or harsh soaps. When you strip your skin of its acid mantle you leave it very sensitive to outside damage. This alone will make your acne or dry skin worse. It can make your skin oilier because your skin thinks it needs more oil because you washed your skin until its' squeaky clean. If you strip your skin it can become very dry. When your skin is dry it makes the signs of aging worse. Fine lines will show up more readily. People who have rosacea should take extra care with their barrier function. MD Formulation's Anti-Redness kit is the best I have seen to treat rosacea without over drying the skin. When women are going through menopause they are at risk of an impaired barrier function. Because the shift in hormones can cause your skin to produce less oil. The change in hormones can also make you break out and be dry at the same time. See if you strip your skin with harsh cleanser your skins water evaporates off of your skin and you can't stay moisturized. Moisturizers help, but sometimes moisturizers will evaporate too! (That's why you can moisturize your legs twice a day and they are still dry)/ Now you could use products that have petroleum byproducts in them and that's fine for your body, but they are too heavy for your face.

What compromises your barrier function.

Wind
Harsh soaps
Smoking
Smokey bars and restaurants
Coffee and caffeine
Traveling (air planes, car heaters and air conditioners)
People who do outdoor sports
Medication (especially acne and hormones meds.)
Hot water
Washing more than twice a day (after a work out is the exception)

Why sunscreen helps.

Sun screens with zinc oxide and titanium oxide can protect you from many of the above hazards.
Zinc oxide is the same ingredient that is in diaper cream to keep baby's skin soft and irritation free. For dry skin it creates a moisture barrier. It keeps water in the skin and environmental hazards off. For oily skin it tricks the skin in to thinking it has enough moisture and it can keep the skin from producing more oil. For sensitive skin it may help it from being reactive to the environment around it.

Cleansers

First stop washing your face with hot water! This irritates and strips all skin types including oily skin. Water should always be luke warm. You should never wash your skin till its squeaky. Your skin should always feel soft when your done washing. Look for a soap free cleanser that is pH balanced. I have more to say on cleansers later on in my posting.

Moisturizers

Water based moisturizers are good for some people, but most people would benefit from a more emollient moisturizer. People are afraid because they think that a richer moisturizer will break them out. Yes some moisturizers are too heavy for some, but what often breaks people out are fragrances and dyes. Some people who have breakouts can cure their breakouts if the just use the right moisturizer. I have more to say on cleanser later on in my posting.

Personal story.

I have a friend who had oily and thin skin with pink undertones. She always had problems with having a reddish nose and always had one or two large pimples. The way she took care of her skin is she used hot water and soap to wash with. She never used moisturizer and only used sunscreen when she was out in the sun. Needless to say her barrier function was severely impaired. I educated her on how she was making her skin worse. I had her use a soap free cleanser and luke warm water. I also had her use a daily sunscreen. Just by doing these things alone caused her tone to even out, she had less oily skin and she had a lot less pimples. (I will deal with breakouts later).

In conclusion do everything to protect your barrier function and your skin will always look great.