I use the plastic containers from JoAnn Fabrics. I purchase them with coupons @ 50% off and they are about $10.00 each. Called Artbin Super Satchel Single Compartment
I like them, have years of UFO's in them. They have a handle, you can see what's in them easily and I actually label the containers for quick viewing. Unfortunately, I have many of them, so I can attest that they stack very well in a closet!