Maybe glue on a window or glass. Watercolor mosaic - really like this idea art journal. Paste paper works too. Great project for a class project, upper or lower grades. Mounting the work on canvas adds a very professional look to the completed collage.
Paper boxes used for the walls as art. Affordable wall art, unique wall display, ways to decorate your home. You can also use art canvas and cut out a pattern from behind it with a repetitive stenciled pattern