1. Pick and choose your fastpasses. During the most crowded parts of the day, a lot of popular attractions will have long wait times, and you don't want to not ride that "must-do" attraction just cause the line was too long.
Don't spend your time waiting in a line that's really boring (ex. Soarin) or really hot (rock n roller coaster).
Here are some rides that i usually NEVER get a fastpass for.
Toy Story Mania :yeah, the line is long, but trust me, the theming is sooo cute inside and its AIR CONDITIONED. your kids will get a kick out of mr potato head, too.
Star Tours: air conditioned
Tower of Terror: A llittle warm outside,but shady, and cool once you get inside and again, themed.
Expedition Everest: themed! stuff to read/look at! The line really sets up the ride, and you miss all of that if you get a fastpass.
Buzz Lightyear: line goes SO fast
Anyways, that's just a couple of examples. You get my drift. This takes a little trial and error.
3. Aim to get fastpasses for fantasyland rides, and ride DUMBO EARLY! It doesn't have fastpasses and the hour and a half wait will make the 2-minute ride seem like a joke :/
2. Book the meals you really want to do before you go (character meals, a restaurant in the world showcase at EPCOT, etc.). That way, even if they are accepting walk-ups, you know you have a guaranteed table and you won't miss out. Utilize hotel restaurants, too. Those can be great experiences.
3. Go back to the hotel for a nap! Especially during the afternoon, you and your kids will be a little worn-out from the heat, crowds, and you'll just be tired. I promise, Splash Mountain will still be there when you come back

Plus, you'll be all rested up and ready to enjoy the rest of your day, and your kids won't fall asleep watching Wishes

4. Save your souvenir shopping for the last time in the park. You'll see a LOT of really neat stuff, and buying all of the neat things you see will add a hefty price tag to your vacation

5. Don't be disappointed if you don't see everything. It's a big, wide world, and there's a lot to do and see.
6. Enjoy your vacation!!
