Measure the driveway where the gate will go and make sure both sides have appropriate gate posts, then draw a design to fit. Driveways can have a single gate across the entire span, or double gates that fasten in the center. They can be made with hinges and latches or an electric opener which slides the gate in and out. Gates are built on a basic rectangle of larger iron with slats, braces and decorative elements welded inside. Start your design by sizing the frame, but locate all other components, with measurements of gaps between posts and spacing of scrollwork.
Lay out the frame and internal elements on a work surface. Use a metal saw to cut bars to size. Decide whether internal spindles will weld to the frame or go through it. Drill properly spaced holes if necessary to fit spindles through top and bottom frame rails. Use a carpenter's square to make sure corners are square. If making a double gate, build two frames.
Weld the frame; miter corners at 45-degree angles with a metal saw and make sure they are square before welding. Lay in internal elements and weld them to the frame. Some elaborate elements, incorporating circles and other scrollwork, should be assembled separately and welded to the frame as a unit. Buy hinges from a supplier and weld them to the gate, then weld or screw to the side posts, depending on what the posts are made of. Add a latch or install an electric opener.