Autumn leaves came to mind when I started thinking about Olivia's September challenge. I think it was the warm brown tones I'm starting to anticipate in the trees and the carpet of leaves on the ground.
The fact that coffee dries darker, unlike watercolour, creates the possibility of layering quite effectively. Its fairly easy to keep on darkening subsequent washes by concentrating the coffee a bit each time. In my case, I did it the lazy way - by just leaving it to evaporate for a day or two in between each layer.