Try not to wait in many lines by using Fastpass efficiently. We were totally spoiled by Fastpass in June, to the point that at night when the Fastpasses were gone, it was hard to deal with.
For example, upon arriving at MK we walked quickly to Dumbo and were the first people on the second spin of the day. We got off, and immediately got fastpasses for Winnie the Pooh on the way to the Raceway which did not have FP and our line was not very long there. By the time we were done, it was time for Pooh Fastpass, but I walked quickly by myself over to Buzz Lightyear to get our next fastpasses then rejoined the family to ride the Barnstormer before Pooh. By then, it was time for Buzz. If you look at the map and think it through, you can do this all day. I would suggest having an adult do any required running around for fastpasses. I met a lady who said what I was doing was too much trouble, but believe me, it was less trouble than entertaining 3 young children in long, hot lines. Hit the rides with no FP early, and always have a FP "cooking" in your pocket. We never ate a meal without one, etc...