A billet of an aluminum alloy or magnesium alloy is formed by a combination of forming operations into a desired article of complex, but open shape. In a first step a billet is heated and extruded to form an extruded workpiece profile having at least first and second sections of different thicknesses. The extruded workpiece may be shaped so that the respective sections are at an angle to each other. The extruded workpiece is then further formed against a forming surface so that the shape of least one of the sections is further formed toward the shape of the article. The methods are suitable for efficient manufacture of many like complex shapes such as brackets and reinforcement members, and even container pans for computers and other electronic devices.