Develop the proper form to pass and bump. Hold your arms straight in front of you and put one palm inside the other, using the space between your elbows and wrists to guide the ball. Cup one hand and place your other hand on top of the cupped palm. Bring your thumbs together so that they face out and away from you, but do not cross your thumbs.
When you bump, you want the ball to hit the inside part of your forearm. This will be more sensitive at first, but it allows you to have a flat, even surface for the ball to bounce off. Practice passing back and forth with a partner, trying to put the ball in the same place every time you pass. You don't even need a net.