If you don't write a lot of notes or your teachers give you handouts, then having one notebook with sections is the best option. Now you don't have to keep switching out notebooks in your bag!
A reusable water goes a long way in making sure you're hydrated during class. Not only can you use this is regular old water, you can put hot water in it and make tea, coffee, and whatever you like. Use this bad boy so you don't have to pay that extra $1.50 at the cafeteria.
My favorite pens to use when rewriting notes! Their tips are small enough to write all the information I need and don't bleed through paper. Although they can see been through thinner paper, they still get the job done. They're also small enough to put in your pocket if you're too lazy to carry a bag.