this is the harder, but better way..

another way is to take ping pong balls, cut em up, put all the cut ups in another ping pong ball, and for a longer lasting smoke make more and more, put a straw in the holw you put the pieces in(cut the straw in half or shorter) wrap it all in tin foil, take a pencil and poke a hole in the side of the ball through the foil, put a fuse (bottle rockets are easy to get fuses from) and light it..its fun haha