These holly leaves are actually crocheted (I wanted most of the ornaments on the advent calendar to be knitted but what can I say, crocheting really lends itself to making pointy things like holly leaves much more than knitting does). I used this tutorial which is VERY well explained so super easy. The berries ARE knitted, taken from this holly pattern and they were also easy and very effective, I think together it looks very Christmassy!
I used this yarn for the leaves and crocheted with a size f/3.75mm hook. The berries are the same yarn in red and I used size 3 needles.