Hey there,
Some really great tips above. If you already have notes from a long lecture it can be useful to create flashcards with just key points. I find the key points are what stick out when you scan read back on your notes and will prompt your brain to start thinking of relevant content so it saves you cramming lots of notes into one flashcard!
If you are preparing for a long lecture, again take the key notes. I find if you try to esentially transcribe everything your lecturer says you don't really take it in. If you can get the main points of the lecture down and try to sit back and listen to the content you may find you remember it better. Of course take any important details like studies etc. down too as these can be helpful for revision.
I hope this helps a bit,
Lauren -Official Student Rep