How to stay pretty all day?

How do you keep your makeup looking good all day? Everyone always looks so great at school, but I look great when I GET there, and then mid day, my skin once again looks uneven and my dark circles have reappeared. My mascara had also gotten flat. What can I do to stay pretty all day? I use bare minerals makeup and neutrogena and almay makeup products, so i dont think its because it is cheap makeup, I think it is that I dont know how to put it on? What are your tips?