Sanding and finishing is an important part of each project. Taking care of, and organizing sandpaper is part of that.
I mostly buy the Mastercraft 1/4 Sheet Palm Sander for the shop. It is $20 on sale, and has an easy to manage dust collection bag. And if it breaks, it is very easy to replace. I keep four on hand - one for each of the workbench electrical outlets.
To go with it, I buy the Mastercraft 50-piece Sandpaper Assortment. It is, frankly, pretty nasty sandpaper. But it goes on sale for $10 a package, has five different grits and works well enough for our purposes.
I find that some students struggle to tear sandpaper to the right size for the sanders. Getting it exactly right is critical for the sheet to be clamped properly by the sander. There used to be a lot of waste. Now I tear the sandpaper down to size in bulk before setting it out for students. It saves time and money.
This is the quick design I made for a woodshop sandpaper caddy. I use it both at school and at home. Each opening holds a stack of 1/4-sheet pieces of sandpaper and/or 5" hook and loop discs. The short pieces of wood on the front face have labelled sample pieces of wood sanded to each of 40, 60, 100, 150, and 220 grit. It also includes a place to store the perforation plates.
Nowadays I also make project packs of sandpaper wrapped in sandwich bags that I give to each student when it is time for them to sand and finish their projects. It is a better way to make sure the sandpaper does not get used up too quickly.