Watch this video to learn how to make an easy waterfall bong in four easy steps. Clean the bowl thoroughly. Look for something to bend the bowl. Mark the cap. Cut a small hole in the center of the cup. Heat up the center to make the whole big enough for the bowl and use a pen to shape it. Place the bowl inside the hole. Mark the bottle where you want the water to drain and burn the whole carefully. Take your bud and load your bowl. Fill with water and you're ready to go.