Did you already send an order to Amazon, e.g. about craft or needlework books ;-)?
You got them then in a books cardboard box from which you can easily make a cardboard Christmas tree :)
Links:
Cardboard Christmas Tree (Christmas tree from Amazon book cardboard box) (Japanese)
Here at unikatissima:
unikatissima’s Amazon.de search / unikatissimas Amazon.de Suche