This is a favourite Christmas Tree decoration of mine, and is made using a technique called Pyrography, where you create a picture by burning the detail into wood. For this one I chose a design of a traditional Christmas pudding complete with a coating of cream and a sprig of holy. I have then added paint, to bring it to life. 
The picture is the same on both sides so it does not matter if the decoration turns.
The wooden slices I have used are made of Pine, complete with bark, and once the paint was dry, it was given several coats of spray varninsh to help protect it from use.  It is hung up using a loop of Jute twine, for that rustic feel.
The slices are 7-8cm in diameter and 1cm thick.