Years ago, I wrote a blog "Having a Green Christmas". I read through it again and the blog is just as relevent today as it was when I wrote it back in 2008.
Christmas simplicity is taking back control over the holiday celebrations and putting priorities where they should be. The holiday is a celebration of the birth of Jesus. Where does that fit in with the holiday craziness that ensues each year? It doesn't. If you take a good honest look at the holiday craziness in your family's celebrations, you may just discover that the further you move away from keeping Christ as the central focus of the holiday, the crazier your life becomes.
In our home, we keep it as simple as possible. We have a small (no larger than 3' tall) tree to place on a desk for decoration. There is also a Nativity creche displayed in the home. Decorations are handmade by the family.
For gifts we limit them to 1-2 per person. Most are handmade gifts, which we prefer. We want to raise our chlidren to appreciate the work and talents of others more than a brand name & price tag. Occassionally, a gift may be purchased but only if it is something we are unable to make ourselves.
T keep Christ central in the celebrations, we have devotional Bible activities for the children. I found online a printable Jesse Tree activity for kids. You can find it at http://tiredneedsleep.blogspot.com/2009/11/advent-and-jesse-tree.html#. The free printable has a link, but the blog post shows how this mom made it.