I take notes during class and color code them - not to any specific system just what I fancy using different colors when the point changes or highlighting certain note phrases among a block of others with different colored ink. Then I hardly ever look at them again. I do all of the assigned reading IF it is not in a text book format - I skim headings and bold / italics etc. if it is a text book format instead. Most of my classes focus on writing papers rather than taking tests - or the tests are essay format etc. so this serves me quite well. For Sciences and Math it's a bit more study but I haven't taken one of those in awhile.