We have actually enjoyed our level 10 days but strategic planning is part of it and really goes hand in hand with your question. We literally have had very low crowds by hitting the early RD and then leaving parks in the afternoon. Then in the afternoon we enjoy the pool, shop downtown, and resort hop.
But to answer your question, below are the things we have enjoyed that don't seem as crowded as other areas of WDW (I will preface that I have two sons who have never been into anything with princesses so those types of attractions we can't comment on):
At MK:
People Mover, Tom Sawyer Island, Carousel of Progress, Hall of Presidents, Country Bear Jamboree, train, Laugh Factory, snacks and people watch and take in all the park details (If Stitch's Great Escape has a short line, no matter how tempting, I do not suggest. It is literally sitting in the dark with weird noises. Kids cry. Waste of time.)
At Epcot:
This is probably the easiest park because you can just take time and enjoy the various entertainment throughout the park. We also have "escaped" and walked to the Boardwalk.
AK:
Not much advice here as this is our go to park on Christmas day but we leave right after lunch - with this strategy we have been able to avoid crowds. I feel the walkways can get very crowded on the various paths/treks. The boneyard can be a nice place for kids to play and take a break but it too gets crowded.
DHS:
So much has closed here that this too is kind of hard as some of the less crowded attractions aren't open. The Stunt Show seating is extremely large so that is a good option. Star Tours use to have a shorter line than some of the other headliners but with the release of the new movie and opening of Launch Bay - and closure to other attractions - I don't expect that to be the case when we are there in two weeks.
Other:
On Christmas evening we had a carriage ride scheduled at POR which was very nice and certainly away from the crowded parks. We've also enjoyed resort hopping to see decorations and riding the monorail. - And of course the pool and resort playground when the kids were younger. From Disney Springs you can take a boat to POFQ / POR and visit those resorts and enjoy a boat ride too.
One last tip:
One year when I was planning and trying to come up with a strategy for Epcot, I read that the "Silver Ball" / Spaceship Earth ride fluctuates significantly throughout the day. If it has a long wait time then come back later. That is exactly what we ran into and sure enough, when we came back later in the afternoon, the wait time was much shorter. We also had the same experience with Buzz at MK. There are some rides where the line will be long all day - and only get longer - but many fluctuate throughout the day.
My best piece of advice is to expect crowds, manage expectations, and go with the flow. Enjoy what you get to do and don't worry about what you miss. Good luck and enjoy your trip!
