As I mentioned, I usually do some sort of card that incorporates an ornament. Most years I do some sort of tree. The simple version is to print them and stick two back-to-back. The more fiddly, but 3D version is to stick three (or even four) in a ring. The flat one obviously works best if you want to mail it.
Here are some new ones for 2016!
These are 3d versions, and I’ve streamlined the process a bit.
After you print and cut three of any set, just crease slightly at the bottom
Just a bit of a pinch is all you need, rather than the full top to bottom centre score
Add a strip of double-sided tape like so, with a fat strip in the middle of one tree
Stick your hanger string/yarn/twine to the fat piece
then stick the sides. If there is a gap at the top, you can stick a button or a pom-pom or a punched star over it.
Of course you can punch a hole at the top and use them for tags, writing the To: and From: on the back.
The back-to-back sticking is super easy, so very quick for kids!