There are two types of ground balls that outfielders will field. First, there are ground balls without a runner advancing. The responsibility of an outfielder in this situation is to keep the ball in front of them and get the ball to an infielder immediately. Encourage a fielding triangle similar to an infielder, keeping the ball in front at all times (drop knee for young athletes is okay).
When a runner is attempting to advance, an outfielder must catch the ball on the run and make an immediate throw. This second type of outfield ground ball involves the following fundamental steps:
For more information, check out my book Coaching the Beginning Pitcher.