It depends on why you want to wear bronzer in the first place. If you're using bronzer to contour your cheeks, then you should apply it to the hollows of your cheeks. You can also put it under your jawline. If you are wearing it to give yourself a natural looking tan or glow, then you should only apply it to where the sun would naturally hit your face. Sometimes bronzer can appear too harsh on your skin, so a trick would be to blend it out with sheer powder.