Baskets make great inexpensive storage items, and they look good at the same time.
Milk crates are great for organizing books, binders, notebooks and records. They are also stackable. Make a handy mini-sewing kit to keep with you at all times. Place small spools of thread, a card of pins and needles, a thimble and a couple of spare buttons in an empty breath-mint tin. Another option is to make a tiny first-aid kit by filling the tin with adhesive bandages, antibacterial ointment, tissues and aspirin.