I love plastic canvas, especially the colored kind because it is heavier. You can make any size box or tray by cutting to size and whip-stitching the sides together and the bottom. You can even make a lid. Cover with yarn or fabric or not. I've made drawer organizers, magazine holders, boxes, etc.
I've also used the plastic mushroom boxes for storing glues, hand stitching supplies for when I handsew the binding to the quilt back, plastic pill bottles for used needles and pins, and no small cardboard box ever goes to waste. If not in use, then waiting for the next idea.
Besides hanging pictures, I came up with another idea for used needles. I made my design wall out of foamcore board covered with flannel. If I needed to pin up a strip or row that was too heavy to stay stuck to the flannel, I tried to pin it, but often bent the pin. Now I use a used machine needle. Much sturdier and doesn't bend.