I made window covers from stuff I had on hand. They will prevent people from looking inside and prevent condensation. When not in use they just go under the mattress.
I cut some black foam board into the shape of the windows and covered the edges with window seal rubber tubing. Then I attached a few Naugahyde tabs on, and glued pieces of refrigerator magnets to the back of the tabs. Finally glued some button magnets to the door. The glue is not a noticeable as it appears in the photo.
A colorful and/or fun fabric is also a good idea and it’s hard to beat Peanuts. The fabric is doubled up so that the characters are on both sides. Velcro holds the fabric wrapped tight around the metal door rod (the sewn-on mating pieces match up) and on the hinge side where adhesive back velcro is on the door and pieces are sewn at the top and bottom corners of the fabric.