What you need:
cotton t-shirts
fabric paint in red, blue, gold, and silver
pipecleaners
large paper plates
brown paper bags

Cut the brown paper bags so that they fit inside each shirt to keep paint from bleeding through.  Take 4 pipe cleaners and fold in half and then twist the end to make a handle.  Spread out the ends to make a firework shape.  Cover one plate in each color of fabric paint.  Dip the pipecleaner firework into a color and then stamp onto shirt.  Pick up the pipecleaner, turn, and stamp again.  Layer on as many colors as you want for each firework!