Look around for inspiration. Note the shapes and textures in your natural environment. Decide whether to make single-element metal art or a multiple-element scene.
Sketch your chosen design elements onto a large sheet of poster board. Transfer your design elements onto clear overhead projection sheets if you want to increase or decrease their sizes. Reposition the various elements until the overall design pleases your eye.
Transfer your sketched elements directly to 24- or 14-gauge sheet steel or steel plate, or cut out your poster board shapes, lay them on the steel and sketch around them with a black permanent marker. Do not overlap any design elements at this stage.
Don wrap-around eye protection before you cut all the design elements from your sheet steel or steel plate using center-cutting metal shears or a cutting wheel on a 4-inch right-angle grinder, depending on the gauge, or thickness, of the steel.
Remove burrs with a bench grinder, using a fine-grinding wheel and a wire wheel.
Smith the steel to shape by hammering and bending it as needed. Hammer thin sheet steel and rod stock cold. You may have to heat thicker steel before working it. Use standard soldering techniques to secure small design elements to each other.
Don a welding helmet, gloves and full leathers. Weld medium and large elements to ensure a secure hold, using a 110 gasless MIG or other welder.
Arrange all design elements as desired, overlapping elements as needed. Solder or weld all pieces. Drill screw or bolt holes where necessary. Add any loops or hangers.
Finish-grind and wire-wheel your project as desired to provide a brushed finish down to clean steel. Add patina or paint if desired, before you apply clear spray enamel to protect your finish.