Stores are already full of Christmas stuff. hawksmont Universe has something for you too Those pine branches should be helpful in your designs.
There are 16 full branches and 33 smaller parts, so you can design you own branches yourself. If those brushes are too big for you, just check out the latest GIMP 2.4 version! You can resize your brushes now
Download GIMP Pine Brushes .zip file
Those brushes are for GIMP application. They have .gbr extension and they won’t work with Photoshop. If you are looking for Photoshop brushes, just search within the Photoshop Brushes category.