Do you study a text by highting or underlining it?

Last year was my first year in college. I had never really had to study for anything before. But when I started classes I bought highlighters paper clips and page tabs. I highlighted everything I wanted to learn that I knew I would forget. It helped so much for tests and stuff. I bought my books for over $500.00 Canadian. I could have just lent them from the school and got a full refund but I wanted it to be like my own career bible. If I ever need to look back I have it. I think it's a good idea to highlight things.. But everyone has different learning techniques.