I've always wanted to do something like this, but I don't have curtain rods on all my windows. It never occurred to me to use a tension rod. They are pretty cheap and easy to take down after the holiday.
Last Christmas - Made an Elf Yourself for our office Christmas decorating. Cut a hole in cardboard covered in paper. Cut out outfit and paste. I had 2 paper rolls on each side to hold so your fingers/hands don't get in the picture. Camera/friends and click the photo.