1) Find out what way you learn best (auditory, visual, etc) and study according to that.
2) Pay close attention to what the instructor says. Sometimes, they will tell you what you need to study or drop hints about what's important.
3) Find a quiet place to focus on your studying.
4) Use highlighters and write notes in your books!
5) ALWAYS do the NCLEX questions at the end of the chapters! My instructors actually put some of those on the test!
6) The app Quizlet is a lifesaver!