TIPS FROM EXPERIENCED COACHES:

The "Basic Skills of Soccer" (dribbling, passing/trapping, and shooting) must be emphasized at every practice, and players must be able to perform these skills sufficiently in order for the team to progress to group or team tactics. Small-sided games of possession where triangular and diamond shapes/positioning is learned, is the next step for group tactics. 

Team tactics can be taught during games if the coach is willing to "coach" off of the ball. That is, as the team is attacking, the coach should be shaping the defense, and as the team is defending, the coach should be shaping the attack. It is an  important "tip" that teams get away from playing in flat lines and  start forming triangles and diamonds to obtain linkage between the defense, midfield, and attack. 

Width on the attack is another important  factor, as the attackers are trying to spread out the defense. "Coaching" on the ball rarely is constructive as the players won't have the time to  process all the information not only in front of them, but the info the  coach is shouting out as well, and only serves to stifle creativity. 

Let the kids play!