This about covers it.

- Read and highlight the textbook before class.

- Go to class, pay attention, take notes and ask questions.

- Go to TA sections and office hours. Come with questions.

- Do the homework with time (ie not an hour before it's due).

- Start studying for exams 2-3 weeks before the exam date.

But most importantly, you really have to want to get A's. Motivation is key. While your friends are out partying and getting drunk you need to be in the library. Sounds terrible, but that's the point. There is a tradeoff. I just graduated with a B+ average. I know I could have done better, but having a social life was important to me. (Also working for Techmeme took up a considerable amount of my time).