We have guests coming and needed one more bed, so decided to make a temporary bedroom in our storage/ work room with a promise to my husband that he could have 'his' room back afterwards.
With finished walls and ceiling, and a window, it was a matter of disguising the workbench and making the room inviting for a single guest.
I did not want to buy things I would have to store when the room goes back to its original function, so with the exception of the folding screen and air bed, everything came from other places in our home.
I used a area rug from another room, borrowed the bench from the garage entry, a cart and plant from the porch, and the clothes rack from the laundry.
We bought a twin air bed and used double bed linen and comforter I already had.
The wall lamp I had stored along wih the nightstand. We even used a piece of scrap diamond plate for a valance. The faux headboard is a artist canvas from previous project.
After my guest leaves, everything can go back to its original home and folding screen and air bed will go to the closet.