Hazelnuts glued together (using a lit to get an even circle) The result is a christmastree-ornament in the form of a wreath! ~I~ You could use chestnuts - and instead of glue - use needle and sisal-string.
Seriously, toilet roll craft is normally AWFUL, but this one is actually very cute! You could even leave off the 'chimney' so it doesn't look like a piece of potentially used toilet paper!) Toilet Paper Roll Craft: Advent Calendar via DollarStoreCrafts