For the perfect party favor, have kids make and bake these clay mini magnet tees

For each tiny tee magnet, roll a small marble-size piece of polymer clay into a long coil. Do this with one or two more colors (A), then twist the coils together (B) and roll them into a ball (C).
On a covered surface, use the side of a can or bottle to roll out the ball into a flat, marbled sheet of clay about 1/4 inch thick. Print out this page, then trace the T-shirt shape on the left, cut it out, and use it as a template to cut a tee from the marbled sheet with a dull knife.
Place the T-shirts on a cookie sheet and bake according to the package directions.
Once the clay has cooled, kids can personalize their T-shirts by adding their name with a felt-tip pen.
Attach a small magnet to the back of the T-shirt with double-sided tape or craft glue. Be sure to have kids wash their hands thoroughly after handling the unbaked clay.