First of all, RELAX!!! Disney is a lot of fun at Christmas. There are a lot of special events and the decorations are great.
However, the crowds will be high and you won't be able to do as much as you can at other times of the year. Since you've been a number of times this probably won't be too bad. Just make sure everyone in your group understands you can't "do it all" at that time of year.
You don't tell us when you arrive (it looks like 12/18 or 12/19), how long you're staying, or where you'll be staying. But here goes some advise:
Crowds won't be too bad when you first arrive. They will steadily grow through 12/24. By 12/25 they will explode. MK will probably close by mid morning on Xmas Day.
Do the major things before 12/25. Even if your first park day is 12/20, you'll have 4 days before Xmas to do the parks. Get as much done during that time as possible.
Unless you want to say you were in MK on Christmas, stay away from it. It will be wall-to-wall people and you will NOT be able to do more than a couple of rides. If you have the time, stay away from all parks on 12/25 as they all get crowded. Try resort hopping, DTD, swimm at the resort pool, play mini golf, etc. If you must go to a park I recommend Epcot. Because it s physically bigger than the other parks it handles the crowds better (people are more spread out) plus not as many children go to Epcot as the other parks.
Use Fast Pass. This is a must for this time of year. Learn how to maximize its use.
Make PS for all sit down meals. It's crowded at this time of year.
Consider booking a Fantasmic Dinner package to avoid the crowds lining up two hours before the show. Usually Fantasmic has two or three showings a night and the later showing is less crowded.
As far as getting on all your favorites, make a list of the must do rides. Get to the park early. If staying on-site take advantage of EMH (but get there just before park opening otherwise you lose this advantage). If not on-site stay away from that days EMH park. Use FP to help you do al of the must do attractions, but stay a little flexible. For example, even if Indiana Jones at MGM is not one of your must dos, if you happen to be walking by just before a show starts and they have space, hoip in the show and enjoy it.
Don't let yourself and your family stress. Crowds can be managed. Just understand you'll have to stay flexible and realize you won't get to everything on this trip (it's just a reason to go back again).
Have fun.
