My daughter brought home this ornament when she was in preschool - I did it in one of my sons' classes for kind. and one for first grade. It's very simple, cheap and they turn out super cute.
You need pipecleaners, red and white clear pony beads, and some ribbon. Basically, they're just beading a candy cane ornament.
I started the first bead - but 2nd graders could probably do it themselves. They take a pipecleaner and put one pony bead on and kind of wrap the pipecleaner around that bead so it can't come off. They then alternate either one red, one white, or two red, two white (depending on how big you want the ornament - you can also pre-cut the pipecleaners to make them smaller). Then they wrap the other end of the pipecleaner around the last pony bead they put on. Bend the beaded pipecleaner into the shape of a candy cane and tie on a satin ribbon. Makes a very pretty ornament for the tree!