Ball moves from left to right and back again as the group moves on 1 line to the other side of the field. Additional extension of this exercise:
Trainer names a player.
Player calls left or right player by name and switches positions. Fellow player crosses behind.
Both with and without ball.
The players learn in this way to coach each other, to see each other and not only to pay attention to the ball. Can be used as warming up as well as coaching training.