String cord or thin ribbon through the holes; knot the ends to hang. Use magnets to stick papers to the metal boards. If your tray doesn't hang straight, stick Velcro dots on the bottom corners of the tray's back
Very easy. Paint an old tray, stress it. Modge podge old music sheet or old book pages. Glue a little old bottle a vintage photo and an old door key piece. I have done this and looks beautiful. Instead of these pieces you can add other fixtures too.