The best attendance booster was the Wizards visits to our school at lunch hour. As part of the package, they will do a convocation or send a couple of players to hang out in the lunch rooms.
I was a guide for the middle school lunchroom and they really got the kids pumped up and even made a special visit to the detention lunch room to encourage them. We gave flyers to each child in the lunch rooms, who took them home to their parents.
I estimate 30% of our ticket sales were at the door from kids who begged their parents to go and brought the flyers. After the game, probably 75% or more of the kids in the audience stood in line for autographs. It was a school night and the parents were allowing them to stay up a little later because everybody loved the show. A real crowd-pleaser and great fundraiser.
If you can get a team of players that other groups will want to see (favorite teachers, community leaders, sports stars......) that will boost your attendance.