Paint your duct work with black heat-resistant paint. Overpaint sections of the duct work in designs that follow a theme, such as night scene with a silver moon and stars, using silver heat-resistant paint.
Create a family history with magnetized foam craft designs. Have each family member adopt a section of the duct work and create her own unique story. Buy magnetized designs from a craft store or make your own by gluing small magnets to foam cut-outs.
Paint your family name in heat-resistant paint along the duct work. Display family photos in magnetized frames along the metal.
Change your furnace duct work magnetized décor with each season or event. Make or buy gingerbread men magnets, Christmas trees, ornaments, angels and presents for Christmas; snowmen, snowflakes and sleds for winter; ducks, rabbits, pastel eggs and tulips for spring; gardening tools and vegetables for summer, and colored leaves, pumpkins, ghosts and bats for fall.