Step 2: Cut the ping pong balls
This is the most tedious and time-consuming step... cutting the ping pong balls.
Although it may sound easy, it might take some time.
First, take one ping pong ball and cut a hole in it about 1 to 1.5 cm in diameter. (Try to make it as circular as possible)
Then, take the other 4 or 5 ping pong balls and start cutting them into the container or bin in little pieces that can fit into the ping pong ball's hole. If they're too big to fit in the hole you might have to go back and cut them a little more to make them fit.
When you're at your last ping pong ball, cut one piece that's a little bigger than the hole (too close up the hole from the inside).
Once you're done cutting the ping pong balls, take the little pieces and stick them in the hole in the first ping pong ball. Then once all the little pieces are in, take the bigger piece and squish it in the hole and then move it around to close it up from the inside.
The second picture is the one with the bigger piece of a ping pong ball covering the hole in the first ball.