Sure, the kids enjoyed the designing, cutting and construction of the masks, but what they loved (more than anything else) was digging their hands into the box of "found objects".
We were lucky enough at the time to work with a public art gallery who often had items donated for the purposes of artmaking. One fantastic woman was known to regularly drop off bits and pieces of old costume jewelery and beads -- lots and lots of beads.
It was a good lesson for us to learn. While it is always great to make art using top of the line supplies that can be purchased, creating with bits and pieces of found items that may or may not have been intended for artmaking, is far more exciting.