I was happy with the way this one started. Before the above photo. I think one of the difficulties I'm having is not planning the colours before getting started and using transparent vs. staining paints in the wrong succession.
The painting below is still a bit tonally flat. The middle foreground shape needs to be dark as well. The hole into the background is also too big. It also needs a pop of colour; maybe red?
Update 12-Nov-12: I wasn't happy with the painting, so added a bunch of rose and violet while it was under wet plastic wrap. That didn't improve it. Was even flatter, muddier, and dark. So I tried to scrub off vertical strips of paint. And this is how it is. This is probably how I'll leave it.
Or I could run the whole kaboodle under the bathtub faucet and see where to go from there?