Keep your face scrupulously clean. Wash with a mild soap (Neutrogena works very well), followed by Witch Hazel used as an astringent. In extreme cases, go one step further--begin your cleansing regimen with Albolene Creme--apply a thin coat to your skin and then wipe it off with a soft tissue, then wash, and follow with the Witch Hazel. The Albolene dissolves the sebum which builds up in your pores and makes it easier to remove.
Wash your fash every morning and night. If that doesn't work try some cleansers. If that doesn't work go to a dermatologist. I did all of the above and my dermatologist reccomended something for me that's really helping!