Participate in orgies and eat a baby, just like every other day.

Here in the US we observe an amalgam of modern and international seasonal holiday traditions, but mostly we eat.

Get drunk, eat too much and watch tele, just like everyone else.

I enjoy time with the family, and I participate in giving gifts. I just ignore the mythical side of Xmas.

The same always. Eat, play monopoly, sorry, life, other games I enjoyed as a kid only with my 2 nieces and nephew.

It's a good thought of sharing and caring not the religion

Thee is no reason not to celebrate Christmas, there are a lot of good things about it. Just take out the religious bit and you are fine.

Celebrate the Winter Solstice with food, beverages, and music making
.

Whatever we want

I wake up, get out of bed, drag a comb across my head. Oh never mind.

I have always celebrated Christmas under that name, although not so much these days as it's not a thing for the people in my life. It was never a religious occasion for us growing up in my family, just a fun time for kids.

During our dark Alaska winters many of us celebrate the Winter Solstice and the returning warmth of the sun ...or sometimes I observe Saturnalia a Roman celebration of feasting and gifts when social norms were reversed and masters would serve their slaves...

I love christmas! I do the decorating and everything else except gifts are homemade only. Lots of cooking, baking, and having fun. Not much fun this year but still happy and a little festive.

Non believers eat, drink and be merry.

Honestly, pretty dull stuff. Eat too much. Drink too much. Irritate the family with gawd-awful Bob Rivers xmas songs and Trans-Siberian Orchestra, but, since you asked, I think it'd also be a lot of fun to create what would likely be regarded as the most inappropriate/insensitive seasonal display for the front yard, with the center piece being a reimagined nativity scene. Maybe some of you could help me out with this next part, as I might need some help distinguishing between the, otherwise central figures, and the 3 wise men. In addition to the usual farm animals, I'd have the wise men represented by Dawkins, Hutchins, and Darwin standing watch over a serene, angelic spaghetti monster, over which would hang an energy drink can (Rock Star, naturally). I'm guessing the typical passerby probably wouldn't recognize some of the other figures on display, but I'm thinking Sam Harris, Michael Schermer, and Daniel Dennett, to name a few.

I celebrate the solstice.

I pretty much do as most Christians do, but without any of the god bothering.

Yup, Winter Solstice for me. I’m not Pagan, but love celebrating the shortest day and change to lengthening days.

Celebrate the winter solstice and eat drink and be merry

It is just another day at my house.

I do the same thing I do every Sunday and other religious holiday celebration. Enjoy a peaceful day doing what I want with people I like - totally guilt free

I do very little at Christmas. If I did not live alone this would all change I'm sure. Merry Yuletide and Happy Sammich to you.

This year got my family all to donate to charity in lieu of gifts....waaaaay less social contact, (no shopping, mailing, touching "foreign" stuff)
We are all older & need nothing anyway.
The dogs will enjoy their presents in the morning, plus mine to me. (The bigger-screen 4K OLED is already installed)
Going to buy myself something lovely for dinner on the 25th...Thanksgiving I roasted a duck. I think a lobster this time......

So, the answers I see reinforce two things I always knew about human nature:

1. we need group rituals
2. atheists practice Christian ritual/culture by DEFAULT

Even our calendar makes us practice Abrahamic law by default

I'm not convinced of the interchangeability of 'atheist' and 'pagan,' but then I'm also a nullifidian.