Do you have overproductive sebaceous glands which are responsible for oily skin? The good news is that sebum helps prevent the skin from drying out. However, oily skin tends to attract more dirt and dust than dry skin. The excess oil production also means that the skin is prone to breakouts. That's why it's especially important to get your skincare regime right.
Cleansing. Cleanse at least twice a day with a mild cleanser formulated for oily skin to help prevent clogged pores. If you have breakouts, use a cleanser with salicylic acid to help exfoliate pores. But don't over-wash because it might dry your skin out. (Yes, it's possible!)
Toning. After cleansing, follow with a non-greasy astringent to remove excess oils. Avoid harsh alcohol-based toners which tend to strip too much oil from your face, and may result in skin irritation.
Moisturizer. Unless you have very oily skin, use an oil-free moisturizer after your toner, and before you apply your makeup. Moisturizer will prep your skin, allowing your makeup to go on smooth and even.
Spot Treatment. To get rid of those occasional spots, try spot acne treatments such as benzoyl peroxide and salicylic acid. The anti-bacterial and exfoliating actions work to kill spot-causing bacteria. Meanwhile, keep your hands off the zits - picking at them can lead to further infection and may even result in scarring.