We make this event our "Welcome back to school" event. We send home fliers with the school packet that goes home at the end of the summer. With our school of almost 500 we usually get around 250 - 300 kids and their families. In regards to the ice cream we keep it simple. We go with the hoodsie cups. You can purchase them at BJs or one of those types of super stores. Normally there like 36 in a package for maybe 6 bucks or something. So we'll purchase almost 30 packages, but the cost is less than $200.
By going this route you don't have to deal with sprinkles, whip cream, cherries, the mess, etc. Simply have your helpers remove the cup lid and stick a spoon in it. Kids come up a grab one.
So by going this route it lets us focus more on the fun of the event, which includes the music, games, prizes, etc.
I have read that many schools have ice cream socials, how many people are in attendance. We have a school of 625 students. I thinking that is alot of ice cream and alot of mess.