This is a drill I use with elementary school boys (2nd to 4th grade so far) that has been popular.  It teaches the boys to move without the ball, and to move/weave toward the basket (to be in a position to shoot).  I’ve found this drill works best with man-to-man defense.

Youth Man to Man Defense Drill
1) Four boys on offense, four boys on defense
2) The point guard starts out with the ball, at the top of the circle.  He may dribble where he likes, but for no more than five seconds.
3) His teammates are instructed to move without the ball, to set picks for one another, and look for a pass from the point guard.
4) The point guard passes to an open teammates and moves toward the basket.
5) The teammate who catches the pass from the point guard cannot dribble – all he can do is pivot and pass to another teammate.
6) The teammates, and all subsequent teammates who are passed to, have no more than five seconds to pass to another teammate or they turn the ball over.
7) The offensive team is to make three passes before shooting, all with no dribbles (except the initial player, the point guard).  A variation on this is to make a small spot near the basket the “trigger” for the boy catching the ball within it to shoot right away.  Another variation is to have everyone on the offensive team to touch the ball before a shot is taken.
8) The offense scores two points for a made basket, one point if they got off a shot and have no five-second, moving pivot, etc. violations.  The defense scores one point if there are any such violations, or if they steal a pass.  If the defender fouls an offensive player, the ball gets re-set.
9) First team to 10 wins the game.  Then switch sides and start a new game.  Play best two out of three, with the loser running some laps.

This drill helps the passer to use his body/pivots to create space between his defender.  Make sure the boys on defense do not fall back into a zone .