Contact Your Professor When You're Struggling Academically
While this advice might seem like mastery of the obvious, it's amazing how many students do not act on it. As a professor myself, I find that students in the A to B range are the most likely to contact me to discuss their assignments and any questions they have regarding them. Students who fare more poorly over the course of the semester often confuse bad grades from a teacher with dislike from that teacher. I know I did. I was so confused by economics, but the last place I wanted to go was to my professor's office for help. When fear of failure won out over fear of embarrassment, I went to see her, and I found out she'd been hoping for a while that I would come by. If you are struggling with the subject matter of a course, the best thing you can do is to let your teacher know. Your teacher will be glad that you are taking steps to improve the situation.
Contact Your Professor When You're Doing Well, Too.
You should especially do this if you love the subject matter of the course you're taking. What if, unlike me, you're doing well in economics and you love it? Your professor would probably love to take a break from explaining the supply and demand curve to people like me and talk shop with a kindred spirit like yourself. One of the best parts of going to college is joining a community of intellectuals where you can learn in and out of the classroom. Stop by and see your professor and find out how to pursue his or her subject. Who knows, you might end up majoring in it. When it's time to write your thesis, and other people are scrambling around to find an advisor, you might not have to because you've already developed this relationship. In addition to thesis projects, contact with a faculty member outside of the classroom can lead to exciting independently designed tutorials that allow you to study intensively one-on-one.
Faculty Contacts Down the Road
Beyond the benefits you'll derive from establishing contacts with faculty members while you're in school, you'll be very happy you did once you're out of school, too. Faculty members with whom you've cultivated a relationship can act as references for graduate school, or for jobs.