Managed to get home to put down the monochrome underpainting which now gives a good idea of the tonal design. I have manipulated the paint to give maximum amount of unplanned detail to try and mimic Nature which I will then start to work on top of to bring out the shadows and highlights, at this point I have been thinking about the way that Arthur Rackham drew trees and roots as the inspiration for the foreground. The paint mix of Burnt Sienna, Alizarin Crimson and Transparent Maroon thinned with Liquin was applied with an old battered bristle brush - a brush never loses it's usefulness even when looking totally knackered!
I am going to have some floating green (?) lights and maybe even a green light in her eyes, not sure yet.