I'm a Whovian. I love Christmas. It seemed like a brilliant idea when my lovely wife mentioned that we had an extra Christmas tree for display in the family room and that I ought to make a Doctor Who Christmas tree. So I did.
Step 1: Cubee Doctor Who Figures
I found some Cubee paper craft Doctor Who figures by Cyber Drone on DeviantArt.com: (http://cyberdrone.deviantart.com/gallery/9187037).
I downloaded versions of the 11 available Incarnations of the Doctor as well as some companions and some enemies. The Cubees are pretty self explanatory but I decided to make them a bit sturdier by gluing the tabs on the seams together.
I also added a loop of fishing line to use as a hanger for each ornament.
Step 2: Add Lights and a Topper (optional)
I was fortunately the recipient of a 50th anniversary TARDIS night light as a white elephant gift at my office Christmas party. I rigged it up with a short length of 1/2 inch PVC pipe, a 3M command strip and a zip tie to slip over the top bit of the tree.