[Damian]

First, most gyms have a beam that runs right above the division line, so look for it. It helps

Second. As an old setter from Volleyball, I would always aim for a spot in space for the hitter to come spike the ball. It works well on the toss. When you step into the circle to toss the ball, you can gauge the height of the jumpers and determine where you want the ball to go. Then, try to toss to that spot in space. Its sounds a little goofy, but it works well for me.

Practice, practice, practice.