How to make T-Ball more fun?!?

I am 18 years old and have taken on a big responsibility of running my towns T-Ball league. I have looked over some suggestions from previous parents and they say that the game needs to be more fun, or "less boring" as they put it, for both them and the players. The current roster size is 15 girls per team and everyone must be put on the field every inning and everyone must bat every inning. I have already come up with reducing roster size to 11 girls per team. But do any of you have any other suggestions on how to make the game more fun?

I am open to any suggestions. It is T-Ball, so all the rules of ASA softball do not have to be followed. We can change pretty much anything as long as it befits the girls. The idea of T-Ball is to start them out, teach them the fundamentals, and basically make them want to come back and continue onto softball.

I appreciate any suggestions, thank you in advance.