Physics and Organic is easy....work hundreds of problems. Seriously, there are no short cuts to being good at these two, you must put in the sweat blood and tears.
As a tutor at my school's tutor center I occasionally get the opportunity to hear and respond to student's study methods. One dear tutee told me she recopied her physics notes from class, copied the homework problems off of the computer based homework onto paper, read the text book, and reworked the homeworks after she finished them. Do NOT try to learn physics this way, or Organic, most of that is a total waste of precious time. Basically use the notes the professor gives you to get the equations, use the examples they give you to see the equations in action and then go practice it on your own until you've got that topic down cold. This works for Organic and Physics, except in organic instead of "equations" it's "mechanisms" usually.
Biology requires whatever you need to do to remember the information. Everyone eventually figures out what works for them. For instance, I'm big on making note cards, but I never actually flash them or use them. Sound weird? Yeah, it is, because just the very act of making note cards the way I do (turning everything into a question or true/false statement) is like making my own exams, by the time I'm done doing it, I know the material and don't usually need to even look at them again. But find what works for you.
General Chemistry is some mixture of the two, a hybrid beast that requires both problem solving skills and memorization of information. My least favorite and least strong area, sadly.
