To start off, my kids school has two coaches hitting to the outfield from next to the pitchers mound. One on each side. They outfielders thrown a ball in through a relay (unless the catcher calls them off) to a catcher on either side of home plate. The players not involved in the relay move into position they would normally be in based on how the relay would be played in a normal game. After that drill, one coach moves to the outfield and hits pop ups while the other hits grounders to the infield.
Its not your normal hit to a position and them have them throw to 1b or 2b. Its an around the horn thing they do. Its up tempo and the idea is go get the blood moving and warm the kids up. Throughout the course of the thing, the kids probably only get 3 - 5 balls hit to them, but they are constantly moving, catching and throwing the ball. No time is wasted sitting around while the coach hits from position to position. We end our warmups with the typical, hit to the position, throw to the catcher, charge in on slow roller and through to first, head in drill. Though our kids do not go into the dugout until the entire team is there, so they wait at the entrance to high five those coming in.
The same as coach2709, you better be ready to go, because our coaches are not waiting around for a kid to sulk if they screw up, or are not in position. In addition we have buckets of balls on the field, any overthrows or missed balls are left to be picked up afterwards. We are not waiting around for someone to retrieve a ball. Finally, the non-starters will get a ball or two hit to them, but for the most part the starters take 80% of the balls hit to their position during warmups. The entire thing takes about 10 minutes or so.