Not an atheist but not a Christian either. I visit with relatives and family. I don't decorate for Christmas or celebrate it religiously in any way. If I had my way I would probably fuse it with New Years and just celebrate that as a gift giving opportunity, although frankly I also don't much care for the exchange idea. And I don't celebrate Easter at all anymore.
I consider it an almost wholly secular holiday for those who are "culturally Christian" by operation of birth.
Pew is instructive as well: I'm in that ten percent or so who attend gatherings and buy gifts, but I do not put up a tree, attend religious services (I will if asked to because an extended, usually Catholic, family member wants it), send cards, do anything related to Santa and I have never, to my knowledge, gone caroling. Sometimes I will listen to Christmas music, although the vast majority of it is secular in nature.
And I do nothing for Easter. That one seems to have fallen out of favor rather quickly, once ripped from the religious context.