Nativity scenes are A Thing in my family. Everyone has one. My favorite aunt gives them as presents the first Christmas after someone gets married (or, in my case, after I bought a house, since pretty much everyone assumed by then that I was never going to get married), and tries to find ones as similar to my grandmother's as possible. I loved setting ours up every year, doing little scenes, moving the Wise Men day by day until they arrived on January sixth.* I keep setting it up every year now, substituting an oil lamp or candle for the baby Jesus to stand for the Reborn Sun. The smaller figures are Poppets, creations of Lisa Snellings, which I collect. Some years I throw in other sorts of figures. When there are kids coming over for part of the night, I encourage them to bring toys to add, too.
One of the things I hold onto from Wicca is the Wheel of the Year. It's so easy to get disconnected from the seasons in our society that I find it useful to have a touchstone for them, something to bring myself back to. I modify them from the usual Wiccan themes somewhat, since those are based on the seasons of the British Isles, and my climate is somewhat different, and I don't necessarily mark them with any ritual more complex than a very seasonal meal, but I do keep them, in my way.
Ancient Hellas was not, as far as I can tell, much into the Solstices, which may have something to do with the low latitude and therefor much smaller variation in day length. When the night doesn't go on and on and on, the longest night is less significant. I live in Seattle, though, and this Solstice night was fifteen and a half hours, which I feel ought to be marked.
On Solstice Night, I keep vigil. I keep a flame, and as many lights as possible, burning all night. I mark the setting and the rising of the sun, and vow to keep the light alive until the sun returns. I cook a lot, usually pork braised in spiced cider or wine and orange juice, and lots of sweet things. Most years, I invite people to drop in any time throughout the night, although that wasn't feasible this year. I listen to seasonal music (WinterTide by Heather Alexander and Alexander James Adams featured prominently this year; it's a good reflection of how I celebrate the Solstice, a blend of traditional Christmas carols, traditional carols that have been paganized, and new pagan songs), watch favorite holiday movies, make my family's traditional Christmas recipes, and carry on any other family traditions I happen to feel like. The metaphorical kinds of light need to be kept alive as well, in the dark time of the year, and family traditions and connections are important to me -- as they were in ancient Hellas, even if my family's traditions are vastly different from those. It's especially important when I'm far away from them, as I am this year, unable to make it back for the holidays. I only celebrate Christmas with my family, as a family tradition, and prefer when I'm not with them to transfer those traditions to Solstice.
I think something that often gets lost in reconstructionist religions is that the timing of holidays is based on seasons very different from where most of us live. In Greece, the summer is the dead time, and traditionally that was when Persephone spent her time in the Underworld with her husband. The world scorched and parched rather than froze. Her return was celebrated with the rain's return in fall. But in more northerly, temperate climes, it makes more sense that she spends the winter below, and returns in spring with the warmth and sun. Anthesteria is a festival for blossoms and for opening last year's vintage of wine. It makes no sense to celebrate it when there's snow on the ground, or conversely when grapes would have been harvested too late for the wine to have matured (although the style in Hellas was for much younger and sweeter wines). The calendar of Greece was arranged around these holidays and seasons (and was often changed, and not the same from place to place), not the holidays around the calendar.
I won't give up my seasonal celebrations, although they don't mean the same things to me that they used to, and I won't celebrate the old festivals and rituals at times that make no sense in my home. City dwellers then may not have lived in tune with the cycles of planting and harvest any more than we do now, but many of their festivals and holy days were still rooted in that and in the changing seasons. I want to respect that aspect of them, and think it's far more important than abiding by a calendar that only had meaning in Athens during a certain period, and that honestly did not have as much meaning then and there as ours does to us.
*Which is the Epiphany, the Feast of the Magi, the Twelfth Day of Christmas. I did pick up a few things from my mother's Catholic family. Another one people these days miss: the Immaculate Conception isn't the conception of Jesus, but the conception of Mary, who had to be conceived and born without original sin in order to be a suitable mother for the son of God, according the Catholic doctrine. I get annoyed when people get these wrong, because I am a pedant, and I see both of these a lot this time of year.