One option is to use bigger cards / paper slips for reading notes, as Umberto Eco advises in his 'How to Write a Thesis'. That way, you keep flexibility on whether to use Cornell Note-style, mind maps, etc. I am not a student, but I read a lot of philosophy or legal texts with complex points and arguments, and this requires larger sheets (I use A5, or even A4 that I fold and have a small folio of 4 pages). Only what fits into my general research topics later, after a review, goes into a box of more permanent notes (on A6).