Good grades automatically follow involvement - but if you are just gunning for grades, you'll end up with a shallow knowledge and an ulcer. I knew this woman who was just obsessed with making As - she'd always succeed but she drove herself nutty and would forget everything a week after the test. Another would make Ds because she was half-stoned all the time and had test anxiety - a few week's coaching and she was making As because she got involved and knew what she was doing. My best tutoring effort ever was to get her up to a B in thermodynamics when she was in last place in the class at midterm - she ended up with the second highest grade on the final, because she stopped thinking about grades and started thinking about thermodynamics, and it started being fun to her.

Point - grades are often meaningless and you should never obsess over them. Think about the material and make it fun and grades automatically follow.