Officer's Mess

"Archmage Dulacar held council on the eve of battle. Though an expert tactician and strategist, he had let every one of his general staff speak their peace. They decided together what would be best for the small unit of warmages. They took the field at dawn in checkerboard formation, with Dulacar at the extreme right flank of the foremost prong. Though outnumbered six to one, they would go on to carry the day."
~Grandmaster Jeren, A History.

Execution

An Officer's Mess is held before the battle. Generally, it is held the night before but in cases where the battle is unexpected, they can be hastily done. Traditionally, the leaders of each unit meet in a commandeered home, tent, or other private shelter. At these meetings, every officer in attendance is expected to speak their mind. It is not uncommon for these meetings to see friendly duels over hurt feelings. The principles of Accordant Concision are in full effect.
The leader or leaders of the force as a whole speak first, with each officer speaking their mind afterwards in turn and giving advise or airing complaints or concerns.
At this point, the commander(s) of the force or at least its most trusted leader(s) choose Tactics and Formations, and normally a rally point will be chosen for armies that are forced from the field to muster after the battle. 
Often, commanders at this point will send a Billet of War to the enemy camp to set terms for the battle.

Components and tools

Typically, a map of the battlefield (even a crude one will do, drawn in dirt or chalk or represented by cutlery)