Schedule a down day in the middle of the trip. There is nothing at all that recharges our batteries like a break midway through our trip. I find that by the middle of the trip everyone's getting tired, and waking up early is getting harder. We take one day to sleep late, have a late character breakfast or brunch, spend the day shopping, swimming, boating, going to the spa, whatever, and a nice dinner that night. The next day we are all ready to get back to the parks and have a new found energy!
As we continue to go more and more often we find that we are now taking even more time away from the parks because we've discovered how many wonderful things there are to do outside of the parks. A day away from the parks doesn't have to be a boring day at all. Some of those off days have been our very best memories of WDW!