Please feel free to ignore, but my DC are now adult and this is what I have learned over the years.
There is no such thing as the perfect Xmas
Go with the flow, ie don't fret if your DC dont want to eat a big Xmas dinner - just give them what they like.
Do not let other relatives dictate the day, this was a biggie for me as PIL would arrive at 9:30am expecting a spotless house and spotless dressed children. DH actually put his foot down about that one.
...and Boxing day is usually more fun !
Any more pearls of wisdom ?