ALTERED ART FOR KIDS. Bookmarks, Tags, and Artists Trading Cards are good first-time-projects. Cupcake tins can be used for sorting objects and styrofoam food trays are perfect containers for gathering supplies for one project at a time. A cardboard or plastic mat will make clean-up easier, too. For girls, have lots of ribbons and pretty papers on hand. For boys, stickers and stencils are popular. All children enjoy postage stamps and fabric scraps.