What a clever way to update an old lampshade (one you already have or one you get second hand). Spray lampshade white and glue/sew old buttons on to create random or specific patterns. Use various shapes and color to create a hodge podge design or go for color specific and/or shape specific depending upon your desired outcome. Goop would be a great (more permanent) glue for this application. This has me thinking about what else could go onto a lampshade to update a room: bottle caps, hat pins, patches, scrap fabrics – it seems end less when you start and think about it.