Here are some photos of the picture frames which will hang on the wall behind my character...
They are quite easy to make, the basic frames were cut out of foam board, and split down the middle to allow for the "glass" to be a little bit separated from the photo, just like a real frame.
Then it's just a matter of spray painting them black. Glass was made from the plastic that comes with most electronic packaging, then sprayed with spray adhesive and dusted with baby powder, to give it that worn and dirty look.
Add some dry brush and voila! Now printed photos will be attached to the backs of these, and they will be hung on the wall.