I would give entering freshmen two pieces of advice. First, find out who the good teachers are. Ask your adviser; poll older students; search the Internet; and consult the teacher-evaluation guides available at most colleges. (As a professor, I am against those guides; too often they are the vehicles of petty grievances put forward by people who have no long-term stake in the enterprise. But if I were a student, I would take advantage of them.)
To some extent your options will be limited by distribution requirements (in colleges that still have them) and scheduling. But within these limits you should do everything you can to get a seat in the class of a professor known for both his or her knowledge of the material and the ability to make it a window on the larger universe. Years later you may not be able to recall the details of lectures and discussions, but the benefits of being in the company of a challenging mind will be yours forever.
Second, I would advise students to take a composition course even if they have tested out of it. I have taught many students whose SAT scores exempted them from the writing requirement, but a disheartening number of them couldn't write and an equal number had never been asked to. They managed to get through high-school without learning how to write a clean English sentence, and if you can't do that you can't do anything.