• know that if you survive your first year, you can survive the rest.
• keep a visual reminder of your goal (mine is a diagram of the medicine curriculum of my school of choice, tacked above my bedpost).
• while you keep your goal in mind, focus on finding your classes interesting.
• choose electives based on your level of interest for them, not based on the curve or how easy they might be.
• do study in advance for organic chemistry (for other classes, do as you please).
• take one summer class if you can afford it (if not, it's not the end of the world).
• keep your sleeping, eating and exercising patterns healthy and regular.
• do find the time to exercise, cook and sleep (for your mental, not physical health).
• do not think of the future too much, but do take the time to find a plan B you love (life is much less stressful when you have an exciting plan B).
• focus on fun in every aspect of your life.
• be organised (if you are, exam period will feel like a holiday, really).
• keep 'study time' and 'leisure time' separate (you will have more leisure time this way) but do make 'study time' feel fun.
• do not underestimate the power of re-reading notes or using cue-cards.
• do not be afraid to ask your professors questions. They have office hours for a reason (and they'll love you just for visiting them). Smile, be respectful and take interest in what they say.
• do have friends and roommates who are not in pre-med, but take their studies as seriously as you do.
• do have friends who are in pre-med, but do not live with them (as a precaution and general rule).

(based on my experience in a two-year preparation program at uni. The curriculum included 2 biology classes, 3 physics classes, 4 chemistry classes (and a lab for each of the previous), 3 math classes, 1 statistics class, at least 2 first-language classes, 3 humanities classes, and 4 social science classes.)