Strip the cloth off the shades; spray paint them copper.
Decide on your button colors/types. Gather a large enough group to complete the shade.
Measure the length between the top and bottom of the shade, allowing for a curve if there is one. Cut copper wire about 6 inches longer than your measurement.
Use masking tape to mark on a table the length your wire (with buttons) needs to be. Layout a line of buttons in a pleasing pattern between the pieces of tape, leaving about 1/4 inch between each button. Once I got going, I would lay out four lines of buttons at a time, to make sure that I was getting a good distribution of colors and sizes.
String your first button on to the wire, leaving about 3 inches of copper wire free on one end. Continue to string buttons until you have reached the right length.
After you have a few wires strung, begin placing them on the lampshade to see what spacing works best. Then you can estimate how many wires you need to make. To place them on the lampshade, wrap the top 3 inches of loose wire around the top bar of the shade, and the bottom 3 inches around the bottom bar.
Once all the wires are strung, and wrapped around the lampshade form, take another look at your spacing and move any strands closer or farther apart to make them even. When you are really happy with the placement, dab a bit of glue on the wrapped wires to keep them in place (we used E6000 glue).