Here I have placed mostly random shapes of color to suggest leaves, branches and other light and darkness found in the shadows beneath the flower. The color shapes were applied using thin washes or glazes of color. These are allowed to dry completely before going further in this area.
This photo shows the first shadow layer over this entire section.
I used a mix of Brown Madder and Ultramarine Blue.
The Ultramarine Blue will give a grainy texture to the shadows.
I will repeat this step lifting color in some areas and darkening in others until I am happy with the way the shadow appears.
Here you can see that I have allowed the shadow color to flow onto the petal. This is so that the edge of the petal will be lost into the shadow and anchor the flower to the background.
I keep the edge of the paint wet just beyond where I want the paint to stop which prevents the paint from drying with a hard edge.
It is important to watch the paint while it is drying in case you need to add a little more water to keep the edge soft.