For a very simple 4th of July decoration, we stamped red, white, and blue bunting. I first made a star stamp by cutting a sponge. I cut out 3 sponge stars (1 each for red, white, and blue paint), and several red, white, and blue construction paper triangles.
To make the bunting, first pour red, white, and blue paint onto paper plates. Then dip the star stamps into the paint and get stamping! At first my son started out tentatively, very precisely dipping the sponge into the paint and coating it.