I know the light is going to hit the back, before it shifts. So I start off by applying a wash of luminous yellow green for the underpainting. The flowers in the front are in the shade, I have plenty of time to work on the foreground.
This #3 Kolinsky sable brush is just right for the flickering leaves.
The difficult part is to see if I can create just the right balance of lights & darks from the setting sun.