I'll add in my vote for the binders. For notes, homework sets, etc., I would often use the backside of white paper printouts (picking up more from the recycle bins in the computer labs when needed).. but eventually I would buy a big box of white printer paper until it would run out. Some classes I'd use engineering paper for homework sets, but it's expensive. I've never been fond of generic lined paper. Spiral notebooks, era, in my opinion very sloppy. You can't temporarily remove papers (for say, xeroxing), if you do remove paper from them, you have all those nasty edges, and if you try to file them or box them, they often get caught up in each other or other things (even your sweater when you're carrying it around).
Now that I teach, I still use binders and white paper... but I do have the binders at 1 per test-based section of material, instead of 1 per class, so I can carry a smaller binder (1 inch, not 2 or 3), and so I can have all the relevant materials, including copies of my notes and examples, copies of my homework solutions, past exams, copies of the chapters' problem-pages (so I don't have to carry around the book)... etc. At the last "review" I can just bring all 3-4 binders. You may want to do something similar if you don't want to carry large weight (that technique has been mentioned here already, I'm just reiterating).
Some people here are also talking about the difficulty of making homework useful for later study.
https://www.physicsforums.com/showpost.php?p=3374196&postcount=5"
With regards to taking notes... I always took notes on example problems and derivations (probably to stay awake...), but I would try to be one or two steps ahead. If I made a mistake, I could cross those lines and correct with some personal notes about where I was going wrong.