Undergrad: Cram night before test, pulled ~4.0 (harder classes required a few additional days of studying)
Med school is a different beast. Look at it this way - you're here to learn. This has been your life's goal, presumably. The more you learn now, the better doctor you'll be in the future. You don't know early on what's relevant for boards (again, a silly way to look at things) or what you could use later on in your career. Do your required ****, go home, eat/relax/see family, then read. Get a decent night's sleep. Go out with friends one night a week (two max, and only long before exams), get good exercise, maintain good stress-relieving activities, keep in touch with family. You will be very busy, but trust me, it pays off. Those who have a natural intellectual curiosity and immerse themselves in whatever material they're learning will do best; as opposed to the "P=MD" and cramming types. Obviously the above won't apply to everyone. But usually to most.
Also, figuring out how to study efficiently is key. I didn't really have to study much prior to medical school, so learning how I learn best was very important. Once you get that down, as well as the quirks of your individual school, you'll do great. Ended up matching into a good program in a very, very competitive field.
