Passing drill: one version is with overlap and other with underlap. In both, most important part is for players to communicate and create movement with and without the ball. Second is that they recognize space where they can go with the ball and where they can run without the ball.

Ball speed, accuracy and of course correct body shape to receive the ball are important technical aspects

Game situations: 

#1 - players use previously learnt overlap (blue arrows) or underlap (red arrows) to perform quick passing combo and arrive into the box to finish. Player that shoots must collect the ball and go to center and wait his turn. Player that started in center goes wide.

#2 - Same as #1 but now with defenders (green). As soon as blue player starts dribbling the ball, one defender goes to press and he attacker needs to play to opposite side (to wide player), who then decides if he wants overlap or underlap by either driving the ball at defender or away from him. Opposite winger can come inside to attack and create 3v2 situation. If green wins the ball they can try to score at small goals.

Key components are:

Communication

Scanning the pitch

timing on passing and uns.

Note: Poles are representing offside line

Size. almost half 9v9 pitch