As already mentioned, get to the parks early, at least an hour before scheduled opening, and hit the most popular ride(s) in the park first thing, that will help to put you ahead of the main crowds flooding in for a good chunk of the morning. Take a break after lunch, relax, shop, go back to the resort for a break and then hit the rides again an hour or 2 before park close. This strategy worked perfect for us Christmas week, especially in MK, EPCOT, and AK. HS not so much. We had our longest waits in HS and the crowds were just wall to wall, even right at park opening. The wait times were crazy high for most of the rides within 30 minutes of park opening.