I rarely wear foundation if I am just going to class or something or I know wherever I am going is going to be hot, because I have very oily skin and I feel soooo nasty at the end of the day. I would suggest either a tinted moisturizer instead of foundation most days, using a primer before your foundation and eye makeup, using a mask or lotion that sucks up oil, and using MAC blot powder or blotting sheets periodically instead of pressed powder all day. I find that when I used pressed powder everytime I get oily, by the end of the day I feel like I have sooo many layers of makeup on, but if I use blot powder it's not as bad.