I just finished making this super easy box. You basically take a 8.5x5.5 piece of cardstock and score it at 2", 4, 6" and 8" (on the 8.5" side). Then you turn the paper around and score it at 2" (on the 5.5 side). Fold over the score lines and then cut it up to the 2" score line... you know what? Just watch this video on how to make it hah. Trust me.. it's easier to make it than to describe how to make it.
Here's how mine turned out :)