One of my approaches to studying while doing my undergrad in Computer Science was to take detailed notes and rewrite them in an online format. The act of rewriting my notes was a form of studying itself. It was a form of studying, but also I felt it would be nice to have them for posterity. They make a nice trip down memory lane for me. And who knows, maybe some future students might benefit from my notes. Then again, they might be led astray due to mistakes and incompleteness.
They look a little like this:
Here they are: