Big bottles of bubbles, sidewalk chalk, lightsaber duels, a ball to play catch with- those crazy balls you get in vending machines work great!- small water guns, spray fans, jumprope, jacks, hopscotch, tarzan- you know where the kids swing on the chains that make the lines- singing loudly is also great fun!
j/k!
I would just talk to the kids and plan your day so you are not waiting on long lines. We don't make spreadsheets or get to the park for opening but we will come back to a ride if the wait is too long. We usually get to ride everything we want with minimal wait times. Have a great trip!