One suggestion. If you are a new PTO leader, we'd welcome you to join our new Facebook group, PTO & PTA Leaders. It's a great place to post questions exactly like this one and you'll get feedback from fellow PTO and PTA leaders.
In the past we used the saying "TEAM...Together Everyone Achieves More". We cut out a HUGE baseball diamond and put it on the cafeteria wall, with the slogan in the middle in big bold letters. We had each class decide what name they would go by all year, i.e. Dunhill's Diamondbacks & Aston's Astros. We made cut outs of a baseball player for each class with their class name on it. Each base represented so many memberships. When a class would get so many memberships, they would inch along to the next base....and so on! The kids got a kick out of it, and the parents would come in just to see where their class was. It turned out great!