All-district teams are chosen by coaches nominating players, and then the players are voted upon and narrowed down to create the team. All-district teams constitute the best players within a given district for that season.
Generally, a meeting is held that all the coaches in the district attend after the season has been completed. The meeting allows the coaches to nominate players from their own team, and they can nominate more than one if felt appropriate. Then, the coaches vote upon players from other schools or organizations within the district. Also, coaches vote for a coach of the year along with the players. Votes are generally cast and counted by secret ballot to ensure fair practice and anonymity for all involved.
Players are nominated for a variety of reasons, including performance, attitude, and work ethic. Multiple players from the same team may appear on the all-district team due to players being evaluated on an individual basis.
Districts vary in rules that qualify players and coaches from entering the nomination process. Some restrictions may be in place if the players or teams aren't signed up with certain local associations or agencies, so coaches need to ensure they follow the requirements to keep their team eligible for the season nominations.