I'm going to share with you all one of our family traditions regarding our Christmas Tree and decorations, which most likely is quite different from your own.
Here is the scenario I will pose: A good friend is pregnant and expecting their first child. Excitement abounds as the delivery date nears and the care and comfort for the expectant mother are primary. The weeks and days leading up to the birth of a young babe include many prayers and preparations.
The day finally arrives, a child is born (!), and then everyone leaves? No! It's NOW that we gather together and celebrate this miraculous event. We travel distances to see our friend (relative) and their new born child! We bring food! We bring gifts! We bring ourselves to share our joy with the new mother and new family!
See where I am going with this???
It's my opinion that we've allowed our retail world to hi-jack this celebration. You see trees and decorations going up BEFORE Thanksgiving! Christmas Music is played 24/7 in our big box stores (I feel so bad for retail workers that have to listen for 30 days to the same shuffle of Christmas classics). By the time the Child arrives - the baby Jesus - everyone has had enough and the day after, December 26th, you'll see faded Christmas trees tossed to the curb, bare of the beautiful ornaments and decorations that adorned it just one day ago! The music changes also - Christmas is over - onto the next holiday....
So our family has pretty much rejected this approach as we are always the last to put up our decorations before Christmas and also the last to take them down as we prefer to celebrate the reason for the season! Before I share our personal story, I'm sharing with you that it was not that long ago that decorating the Christmas tree on Christmas Eve was not that crazy! In fact, in the movie "The Bishop's Wife" (a Christmas Classic and favorite of ours), Dudley decorates the tree on Christmas Eve, allowing Matilda, the maid, to go be with her family. (Click the pic to see the video)
In yet another Christmas Classic - "It's a Wonderful Life", the family is busy stringing popcorn and placing ornaments on the tree as George Baily ponders the missing $8,000 on Christmas Eve. 
To make one more case, I offer little Cindy-Lou Who, who inquires of the Grinch why he is taking their Tree. "There is a light on the tree that won't light on one side. So I'm taking it home to my workshop, my dear. I'll fix it up there. Then I'll bring it back here."
(Ok - This one is probably a stretch...:-) ) To share the book, rather than the TV Show or Movie - >>>> How the Grinch Stole Christmas .
In other cultures - mostly European, it's long been a practice that the tree was not to be decorated until Christmas eve -. "The German Christmas tree (Tannenbaum) is usually put up and decorated on Christmas Eve, though some families opt to erect their tree during the Advent season."
One other observation as a Catholic - it is only AFTER Christmas that we sing traditional Christmas songs in church, not before.
I guess for us, this really took hold (the delayed start of decorating and putting up our tree) once our oldest went away for College (even though he was about 10 miles away attending the University of Kansas in Lawrence). The point was we did not want to put up our ornaments on the tree without him, so we would wait until classes were over and he could join us. This actually paid off over the years as the longer we would wait, the more of a discount we could get on our live tree as the stores were looking to get rid of them. The downside - obviously, was that these trees had been cut and standing around for weeks. Anyway, on our last Christmas in Kansas before moving to Florida, we scored our biggest tree ever, a 12 footer, for $10! I think there were only like 5 trees left on the lot, and this was one of them.
