I used two sizes of pictures in the house. Most of the big ones go on the walls and the little ones mostly set on mantles and tables. I had a few larger frames but I wanted to make more so I made molds of them and made some more big frames using polymer clay.
After cooking and cooling them, I just painted them all gold and added pictures. I glued these frames right on the walls. I can bake clay right in the mold with these molds.
The little frames were made with a mod podge mold. I just dusted the mold with corn starch and filled them with polymer clay, popped them out on a baking pan and into the oven.
I also painted them all gold. You just put some old pictures of your relatives in them and make little cardboard backs that stand up. They can easily be moved around to table or mantel and they add so much to the realism of the house.