I can tell from the various threads that there are many people here that have no personal god(s). It also seems from various threads that most of us nonethetless celebrate at midwinter with friends and family, and may or may not call it Christmas or Hanukkah or whatever your family celebrated whether secularly or religiously... so I was wondering what you do, and how you do it.

We celebrate the solstice (because it actually happens, to the whole planet) as the beginning and end of the solar year (the earth's full orbit). My kids and I, and any close friends who can/want to, go out for dinner and drinks, and have toasts, and I sing a lot of solstic-y songs (my latest fave is Dance with the Dragon by Anne Lister {aka Tabster, here} on Waiting for the Hero which EVERYBODY SHOULD BUY RIGHT NOW BTW).
We do the big family (my Mom, her daughters and any boyfriends, their children and occasional boyfriends) celebration AT Christmas because that is when people have off. Some (like Mom, who's an atheist and a jew) insist on calling it Christmas, but most of us don't really call it anything. I call it Midwinter. It's at my eldest sister's house. We have Hungarian food Christmas Eve, and the next morning open presents and pretty much hang out in PJs and play with new toys all day. We have a big dinner that evening with ham and turkey and trimmings. Then on the day after Christmas aka Boxing Day or St. Stephen's day, my sister hosts the extended relatives (our uncles and aunts and cousins and even more distant kin) and all the close family friends come for a many-hours-long buffet of various courses, including more Hungarian food like korozott (imagine short umlauts on the first o's and a long one on the third), and then all the leftover turkey and ham and fixins and Hungarian food from the night before and it's yummy yummy yummy.
To me, what's important is the (a) element of a cycle turning, out with the old in with the new, stay up late and drink a lot with people you love and who love you. The other element is that of giving things to people. My kids were trained when small to read (or have read to them) the card, get the attention of the giver if present and announce it otherwise, and make sure the giver gets to see them open any presents. The thanks are immediate, and they understand that seeing the pleasure of being a good gift giver is a gift in itself. They are both good shoppers when we go shopping for presents, and really think about what people would like to receive (which is good, since I'm always more interested in what I would like to give!)... they are, of course, big time into GETTING presents, but that isn't the focus of the holiday.

I re-wrote a song for the occasion, it's somewhere in the Forum and never made it into the Trad. I'll find the link later.

Merry Midwinter, all! And to my fellow godless 'catters, please tell what you celebrate, and how, given that the religious holiday season doesn't apply to you... we could all probably use some ideas! Especially if children are involved...