like i've said in many other posts:
1. work hard on your pre reqs for medical school....those A's are the most important
2. go to class...you can almost guarantee a higher grade than a B by consistently going to class and actively learning
3. do not stress over a B if you get one....try something new next semester to improve your grades.
4. if you work hard all semester, it makes finals weeks so much more easy because you will know your material that much better in which achieving an A becomes a consistent manner in your education instead of 'I GOT AN A!'
5. expand your horizons, extracurriculars, work/jobs, shadowing experience, and research
6. start recording/keep a journal of everything you do related to medicine, that way your personal statement will rock
7. enjoy your breaks...don't be stuck in a library...adcoms want human beings not books in their schools
8. you are in college, find a hobby, take cool classes that you will never take again
9. slap a gunner
10. maintain your emotional, physical, and mental health