Cecile’s column about burning wrapping paper in your fireplace, and why it is dangerous, is timely for this time of year. https://www.straightdope.com/columns/read/2684/deck-the-halls-with-balls-of-fire/
I’d like to add two things about burning “der Tannenbaum” as being another rather bad idea.
If you read the part about why paper is bad (surface to volume ratio being much higher than wood) then stop and think about all those tiny needles. Now you really have some surface to ignite! Try burning a few limbs outside in the back yard sometime to see just what this can do. A whole tree? Woooooof!
Burning hardwood (oak, etc) doesn’t create much creosote in your chimney. Soft woods (spelled Christmas tree) is loaded with resins and will coat your chimney is no time flat.
Forewarned is forearmed!