For general work and rough drafts of assignments, I use pencil. Standard stationery: rubber, sharpener, compass, set square.
I use pens for anything that either I'll need to read in the future or someone else will need to read. Lecture notes, final drafts of assignments, any extra notes.
Hole punch and stapler for processing assignments and printed lecture notes.
I use either ring binders or lever arches for my written notes, assignments that I've got back and printed notes. Plastic folders for completed assignments, to keep them neat until I submit them.
Whether or not I write notes in the lectures depends on the module(whether or not they have printed lecture notes(if so how good they are), how hard the module is and how much there is to remember) There were two last term(geometry and physics foundations) that I think I really benefited from writing notes, but at the moment there aren't any that I think it would be useful for so I don't.
For the supervisions and other classes, no. We often have to solve problems so I tend to jot down ideas as I go, but not in a way that would really make sense to me in the future. I sometimes scribble down the name of a particular function etc. that comes up to research it further later.
For my free time: doing questions, reading notes, reading books, thinking, writing lists of the key ideas of a module, proving some of the statements.
I'm doing maths and physics.