First I clean with Jiff, a white abrasive porcelain cleaner, and a green scourer.
Next, the power drill with a flexi shaft and a set of rotary wire brushes, I prefer copper to steel.
Next some Metal/Chome polish, Glow or Autosol. I use a tooth brush to apply and a small brush in the drill to polish.
Finish by hand with metal polish and a soft cloth.