Sounds simple -- if we know what causes acne, we simply need to avoid that behavior to avoid acne, right? Well, the problem is that we really don't know exactly what causes acne -- although we know many of the involved factors.
And guess what -- one of those factors is makeup! Acne reflects clogged skin pores ... and the wrong cosmetics will cause your pores to clog.
How to avoid it? Well, the best way is to take care of your skin. Keep your skin clean -- wash your face at least twice a day. Always make sure you remove all traces of makeup -- if you leave no residue, it can't clog anything.
How's this -- don't use hot water when you wash your face! Instead, use cold or lukewarm water. Hot water can irritate your skin and leave your pores open. This makes it easier for bacteria to enter. Be sure and always finish up washing by rinsing your face with cold water.
Use soap, but choose a soap with an added moisturizing lotion. You may have to pay a little extra for face soap -- but regular commercial "shower grade" soaps may contain harsh ingredients that strip moisture from the skin.
Wash your face -- don't scrub it! Gentlely stroke your face to avoide scratching. Hard scrubbing can actually irritate an existing acne condition.
Finally, look for oil-free cosmetics with natural ingredients. This lessens the chance of clogging pores and may leave your skin healthier. Many folks want to use cosmetics to "hide" imperfections -- but where are these imperfections coming from in the first place? Use the right cosmetics and you can help eliminate the imperfections in the first place!