The Tokyo Shinto Youth Association (Tokyo-to Shinto Seinenkai) has put some downloadable PDFs online for papercraft items for your kamidana. There is an ofuda-tatë, which is something to lean the ofuda against so that it stands up, a pair of koma-inu, and a pair of lanterns (which should not actually be lit because they are made of paper.)
The page and instructions are all in Japanese, but there are instructional videos, so they should be usable even if you cannot read Japanese. The download links are the things with PDF and file sizes written next to them, and everything is available in both colour and black-and-white. (The larger file sizes are colour.)
I haven’t tried to make them myself, so if you do, let us know how well they work.