Do you have a plan for kids to be active as soon as they arrive in your gym? One simple idea is to create an "ASAP Board" for the hallway outside your gymnasium door. You can list the instant activity for kids to begin upon entering, and for your youngest students who can't read quickly, the classroom teacher can read the instructions to the class as they drop off the students.
For our middle school lunch recreation we organize our gym by providing 24 yellow and 24 blue pinnie jerseys in a basket. This limits the action to a safe number of participants on the floor and identifies which activity they elected to participate- yellow for volleyball and blue for basketball. This keeps students committed to their activity with less chaos and increased safety.