We have success--almost. I need to add trim around the edges, and I need to finish spray painting the base, but I am giddy on the inside that I have nearly accomplished the task at hand.
Okay, what I started with--base from Goodwill. Shade marked 75% off at Target. Fabric and spray paint from Hobby Lobby. I bought two yards of fabric to cover two lamp shades, and that seems to be just the right amount (with a little extra) to cover these large shades.