Sailboats make an interesting metal sculpture. By using lightweight sheet metal, you can bend the metal into a shape that looks like a sail blowing in the wind. These sculptures can be free standing or mounted together for a wall hanging. If using as a wall hanging, group several small sailboats with sails at different heights for an interesting collage.
Use different lengths of old duct-work to make sheet metal creatures. Duct-work comes in many widths, so it's easy to use larger pieces for bodies and heads. Thinner pieces can serve as arms, legs, beaks and tails. Duct work is also easy to trim with sheet metal snips, so cutting out eyes, teeth and claws makes appropriate accents to your creatures.
Use metal to make abstract shapes to use as garden sculptures. These pieces can be either large or small depending on the size of the space you want to fill. Large metal garden sculptures can double as benches, while smaller pieces can serve as bird feeders and bird baths. Tiny animal sculptures along a garden path also add interest and whimsy to any outdoor space.
Construct people out of metal for more outdoor interest. Metal people sculptures can be flat and almost have a one-dimensional look. Use these characters in different scenes along with metal cars, bicycles or benches. Add everyday items made out of metal to give the people more personality, like umbrellas, hats and bouquets of flowers.