I was reading this magazine, and the sisters who founded Benefit cosmetics had a great tip. Put your lipstick on, if you wear it, before all your other makeup.
Especially if you're a beginner, this will really help.
If you put on blush and eyeshadow afterwards, you can find yourself using less and avoid overdoing the cheeks and eyes.
Buy it: Benefit lipstick ($16), Benefit and department stores.