I found this really great tutorial on making pencil cases by weaving yarn through a plastic canvas. I love how there are so many different ways to weave the yarn pattern to create a different look. Check out Diane Gilleland's free pattern that is very thorough on how to make these cute cases. (My button is monstrous in comparison to the rest of the case, but I was too lazy to get another one!)
After making this first case, I was inspired to use my leftover plastic canvas and yarn to make another pencil box with the same pattern idea:
Like the above case, the only basic materials needed are yarn, plastic canvas, and a yarn needle. I actually broke my plastic yarn needle as it was slightly bigger than the holes in the canvas, so I actually bent a paper clip into a makeshift yarn needle and found that it worked out really well.
After weaving a yarn pattern on each piece, sew them together to make a box. (See Diane Gilleland's tutorial for details on weaving the yarn)
Sew buttons on the side and tie yarn loops on the lid of the box to make "button holes."