Dribbling around the square is a simple and effective warm-up to get players moving and working on dribbling.
Create a large square with a smaller square inside. Position four lines of players around the corners of the outer square. The first player in each line needs a ball.
Players dribble around the corresponding cone in the center, then dribble or pass to the next line in a rotation.
This exercise can work great in conjunction with a dynamic warm-up because the players will already be in lines. Coaches can have players perform different dynamic movements before adding balls. Once balls are in play, coaches can have players work on different turns, dribbling, or passing techniques.
As a rule of thumb, if there's more than three players in a line, it's best to build another grid so that there's not too many players standing around at once.