At some point every Advent or Christmas season (usually Advent), I turn on George Winston's December and sit by the tree with all non-holiday lights in the house turned off.
I've written about this on here before, years ago. It's like my yearly meditation time. I listen to the piano music, I watch the lights, I watch the shadows caused by the lights, I watch the play of light and shadow on the ceiling, and I just think about my life, the world, people in my life--both past and present, what was, what is, what might have been, and what might be.
Sometimes the CD goes around several times. Sometimes I go to sleep for a bit. Sometimes I pray, sometimes I talk to myself, and sometimes I'm silent the whole time.
It's my little slice of heavenly peace.
My favorite thing to do is imagine the lights on the tree as some sort of analogy, and play with different ideas of what they lights could be. I get as many different colors as possible, all individually blinking... so it could be anything. The "little light" of different people shining out and going away. The prayers being sent up. A sped-up version of lives on Earth.
Or, just pretty blinking lights.
Sometimes I will do this more than once a season, but it happens every year--or every year I put up a tree, anyway!