- Talk to your advisor about taking the right combination of courses...like Don't take 4 hard Math classes at once.
- Figure out why you failed? Not prepared? Didn't go to class? didn't do the reading? didn't do the homework? didn't study? Partied too much? spent too much time on sports? Mental health issue? Girl/boyfriend/family issue? Worked too much?
- Read these ideas: http://talk.collegeconfidential.com/college-life/1920853-college-is-a-step-up-from-hs-16-tips-on-doing-well-in-college.html
- Maybe take less credits (but still full time) next semester so you can do better in less classes?