Get to the parks early - MK was closed by 11:00 am last year --- Epcot absorbs the crowds well since it's so big. Take a break in the afternoon, use Fastpass or ride the "big" rides at Park opening (last year, when we went back to Epcot for dinner after a break - we saw that Test Track had a 3 and 1/2 HOUR wait!!) --- Make a PS for dinner, or else plan on counter service. Don't forget to Thank the CMs for working on Christmas day (or at least be kind to them - it's their Holiday too, and many of them aren't able to be with their families so that we can have fun at WDW with ours...)