The optimal number of players is 12, but the exercise works with 10 - 14 players.
Split the team into two groups of 6.
Set up a 5x5 or 6x6 meters small square 20-22 meters apart from the goal. 
In this area there is the team (Blue) in possession (6 players) with a ball. 
The players of the other team (Red) are placed between the poles (3-3) of the wider area (8-10 meters) as seen. These players work together with one ball and they put pressure one by one in the other area on the coach's command.
One goalkeeper is in the goal and the coach stands with the balls next to the area as shown.
Teams change their roles and positions periodically.

The progression starts on the coach's command. First two players in Position 'A' and 'B' passes their ball to each other by one touch in the wider area. When the coach signs, the player in Position 'A' sprints into the area of possession as fast as he can. Players in possession start to combine with one touch against the incoming defender and try to make 6 passes without a mistake. The defender's role is to touch the ball or forcing the players in possession to make mistakes.
While the possession is going Players in the other group passes their ball to each other by one touch. The ball can't stop. Player 'A' is replaced by the next-coming team mate.