9-30-15: I "ghosted" in the largest of the elements that I want to layer, using transparent white, with the intention of setting them into the composition to make sure that placement and scale work out. Then these elements can be over-painted as color dictates.
At this point, I have switched from acrylic to oil paint and will finish off with oil from here on out.
I'm busy working on my blog posts. Watch this space!