Ooh, in the category of "little things" ... try to get to ride with the driver on the monorail. It's pretty much a first-ask, first-served thing, and if the "engine" compartment is empty at your stop then you can ride up front. Kids get a cute little honorary driver's license at the end of the ride, it's really a cool thing to do that doesn't cost a dime extra.
Also, since you've got a daughter, if you happen to be at MK very early and get to the gift shop behind the castle first, be sure to ask at the register whether Tinkerbell has woke up yet. It's explained better than I can
as one of the tips in this thread.
And do a little advance research about "hidden Mickeys" which are a fun thing to look for throughout the trip.