So I live in a basement apt. I made this cat staircase out of shelves so my cat can get outside but I don't know what to do with the rest of the wall. It's got a weird window. It's in my living room and my main source of light. Any suggestions for window treatments, wall ideas (paint, paper, decor etc). I rent so must be renter friendly. My style is a mix of MCM and boho cozy.