I do not think that there is only one right way to study. People have different methods of processing required information, and there are many ways of obtaining a better comprehension of coursework. My go-to study skill/tip would be to pace myself. When I do this, I grasp the information better and it helps me to get it into my memory. When studying outside of class for a 3 credit course, I would recommend studying for a total of maybe 2 or 3 hours a day, and a total of 6-9 hours a week. Studying is a logical resort to understanding the topic you may have an exam on, and it will significantly aid your comprehension levels on different assignments.