We hash it all out. Do we put the books on the lower shelves randomly, or put like volumes together? I wanted them placed in any old order because it would be a lot of trouble to sort them and keep all the same spines together. I lost the vote, and the effect was much more true to what you would see in a life-size bookstore. It WAS a lot more work, by the way!
The larger pieces, like the comfy chair and table were bought. They are the cornerstones of the scene, but the fun and uniqueness come from the other touches. The book covers (downloaded from the Internet and shrunk to size) happen to be all from my new publisher, Berkley Prime Crime! The rolled up "maps" in the left corner are really scraps of newsprint. The holder for the maps is a plastic cover from a small spray can of ... I can't even remember what. I keep anything that looks remotely like it might be useful someday.
After this photo was taken, a few more things were added: a sign that says "Mysteries," a poster of Agatha Christie under the one of Edgar Allan Poe, and more books on the table and floor.
We spread all my junk on a table and browse through for added touches. I forget who thought of placing a dime on the shelf for scale, instead of the usual ruler. It doesn't matter; it's a joint creation.
Part of the fun of doing projects with friends is that they see things I might not see. Now that I think of it, it's not too different from how my writing critique group works!