Working Together as a Referee Team:
In matches where Assistant Referees are used, the two ARs and the center Referee work together as the third team on the field. The main tools of communication among this team are proper use of flag signals, eye contact, and good positioning. Here are some pointers (not intended to be a complete list) on how to have successful teamwork among the Referee and the ARs:
Referees
If you have time, go over these points and others (such as whether you want AR help in calling fouls they can see but you cannot) in a pre-game discussion
Before you whistle the opening kickoff (and before every kickoff restart - see below), make eye contact with each AR to check that they are in the proper position with flag unfurled and are ready to start the match
During active play, as much as possible try to keep the play between yourself and the AR in that half of the field. While your positioning will be dynamic depending on the play, think of being on a diagonal between the corners of the penalty area furthest from the AR in each half of the field.
Make eye contact with the ARs during stoppages in play - and they should make eye contact with you. This helps with communication and involvement during the match.
When the ball goes in the goal, the first thing you should do is make eye contact with the AR at that end of the field. If the AR's flag is up, unless you saw the play clearly and you are confident there was no offside infraction, blow your whistle and give the signal for the indirect kick and tell the players "offside - no goal". If after making eye contact the AR begins to sprint to the halfway line, you can give the signal for goal, and then move to the center circle for the kickoff
Prior to each kickoff, make eye contact with each AR to check that they are ready.
NOTE: If you have missed a call by the AR at the end that the goal was scored, the hope is that this last eye contact check will indicate that the AR is NOT ready, and you should go check with that AR. Remember that once play is restarted after being stopped, whether for a goal, offside or a foul, the call cannot be reversed - but it CAN be corrected if that restart has not yet taken place.