Nighthawkinlight teaches you how to make firework hemispheres. You start with a softball that will be the basis for the strips of paper you construct the hemispheres from. You take craft paper about an inch wide and soak them in a thin wheat paste. You start applying them on the softball in a pattern that doesn't create a lot of layers on top of each other. You need to spin and squeeze the shell to let all the air out. After you've added two layers of paper, clean off the excess wheat paste with a towel. Take a sharp knife along the middle. You can let it dry a bit, this might help. Also, clean the resulting hemispheres and let them dry.