Since I left my parental home I never had an own Christmas tree. Occasionally a candle were lit and Christmas cards were standing on a shelf to have a little of the atmosphere in my home. I guess the main reason for this was that I wasn’t at home with Christmas anyway.
Yes, also atheists enjoy the Christmas atmosphere. I see it more as a Holiday of peace and rest than of religion. It’s maybe a little bit early but I already wish everybody Merry Christmas.