Take a look at these cool masks made with cardboard! Your middle schoolers through high school kids can have fun with this. Be sure to see the 2 incrredible dragon heads made from cardboard–they are linked on the right sidebar of the mask Instructable. They are probably more in the adult skill range, but simpler dragon heads can be made by kids.
The materials are cheap, the kids can be very creative, and they might even make their own costumes for next Halloween or a very cool wall decoration for their room. Some could be a nice gift for a friend or family member too.
Click title for link at Instructables.