I start with a pencil sketch to lay out the composition and establish the values I want.

I sketched the basic shapes onto the paper and with the value sketch and a photo for reference I'm ready to start.

Here I've started with some background washes of Naples Yellow, Raw Sienna, Burnt Sienna, Burnt Umber, and Cerulean and Manganese Blues in the water.

The next step is establishing the darkened areas in shadow and starting to define the cliff structure more.  I'm still working in the same basic colors.
 

This stage involves more darkening, starting to add Permanent Magenta and Winsor Violet to the rock wall, and Cobalt Turquoise and Prussian Blue to the water.  I've painted these cliffs before and I like the abstract quality and the simplicity of working with just two subjects and nothing else.

The colors haven't changed except for the use of some Titanium White and some Sap Green in the water.  While the water was wet I couldn't paint on the rocks without getting my hand in the wet paint, so I turned the painting upside down and worked on the granite wall that way.  Since the whole thing is fairly abstract anyway this works just as well as painting on it right side up - maybe even better!

I thought the picture upper right was finished, but the more I looked at it the more it bothered me that the lines in the rock on the right were taking my eye up and diagonally out of the picture at the top.  I decided to darken the rock on the right to make the lines appear more vertical.  While I was at it I darkened the crevice in the middle to make it deeper and more interesting.  I also expanded the wave splash on the left to make it more interesting.  I think it's finished now, but who knows - maybe something about it may start to bother me and I'll be back at it again.  I have to live with it a while to know if it's really finished or not.