Begin by cleaning the surface of the object you want to paint. Sanding a metal object with 100-grit sandpaper will help ensure the pain adheres to the surface.
Apply the first coat of paint (metallic copper or gold). You don't need to worry about brush strokes or paint runs at this time. Work from the top down towards the base on tall objects.
Allow the first coat to dry, then use a sponge to apply a coat of dark green paint. Simply blob on the paint leaving enough space between blobs for the gold or copper to show through.
Wait for the dark green paint to dry, then apply a coat of light green paint, again using a sponge. Apply the light green color in an irregular pattern overlapping the dark green color, but making sure you leave small bits of the gold/copper color showing through.
Once the light green paint has dried you can evaluate the finished look. If you aren't happy with the appearance, you can adjust it by daubing on more color or even applying some streaks of copper/gold to achieve a look you like.
Give your project a final touch of realism by applying a light coat of watered blue/gray latex paint, then blotting it with a paper towel.
Finish your verdigris project by applying a final coat or two of a clear acrylic or urethane finish to the entire surface.