Depends what type of subject really. Strangely enough coming from me who's probably known for writing excessive amounts of notes, I'd say writing out notes is extremely ineffective as a study method. However, they simplify things come exam time when you actually do need to cram hard for rote learning subjects. I'm pretty sure this applies for most, but at least for me, what I learnt in these kinds of subjects never stuck in my head for very long. Instead, I'd pretty much write out all the notes during the semester so that I don't waste time when exam time comes around, and then prior to the exam with notes in hand, just memorise everything mostly through rewriting out lists and definitions whilst speaking it out softly (as TSFX would recommend; the more senses involved, the better). I also helped and taught a lot of friends throughout the year so that was probably my other primary source of study, and TSFX does rate teaching others as the best form of study. As for things like maths, sitting down by yourself or with a tutor and conceptually understanding things first is best, followed then by grinding questions. As for English...write essays, read through the book/study guides, and get some good feedback on your essays. Rinse, repeat, fix your mistakes and you should get progressively better.