My co-worker said that they were a hit and they were relatively easy to make (although making 40 of them did take a bit of time).
The 4"x4" boxes started out with 6" x 11" sheets.of Garden Green card stock. I scored on the long side at 1", 5", 6: and 10". I scored on the short side at 1" and 5". I then cut in 1" on each of the scores on the long side. I made sure to use my bone folder to get sharp edges for my boxes and taped them together.
I made belly bands and flags out of Tangelo Twist, Pacific Point, Rich Razzleberry and Real Red. To get the right look for the masks I used the gift box punch in the center of each belly band and attached the flags to the back. I punched 1" circles in Whisper White and 1/2" circles out of Basic Black for the eyes. I cheated a bit and used my e-cutter to cut out the mouths and tongues.
I'm usually a big stamper but delving into punch art was fun. Here is a shot of my little treat boxes ready to go off to the party.