Don't overestimate your abilities. I'd recommend going overboard from the get-go - study ahead, meet with professors, find smart friends to study with, get a tutor if offered, etc even if a class does not seem so difficult. Most people I knew from mine who were not happy with a grade lost the majority of their points in the first half of a class, so you really want to try your best to start off strong. Recalibrate afterwards if you are happy with your work ethic.