People say to reduce oil and fat in your diet, but the experts say that one has nothing to do with the other (unless you are slathering your face with the food you eat).

Mud masks, warm water on your face, astringents (like witch hazel and alcohol-based products) and drying soaps all can help reduce the oil. Also, avoid oil-based face products, like makeup and moisturizers.

Personally, what got rid of my oily skin was a course of Accutane, but unless you have cystic acne to go along with it, that's too drastic.