Starting to wash in the sketch using a large brush. Immediately I want to get something down on the canvas as tones & values - otherwise, I'll worry too much about detail & color & not the overall painting.
Another good reason to use the same color wash all over the painting - as I apply layers, that color will serve to unify all the elements. I can leave some of it showing through the entire process. Or, if applying thin layers, the end result always includes that first layer of color.
Why burnt sienna & cadmium yellow? Well, it helps that Wickers is such a rich chestnut mare. Also, it's just that I have always loved those colors. An artist's prerogative!
Note: this process is NOT a hard & fast set of rules. It's how I'm approaching this oil with this subject at this time. I have a vision in my mind about how I want this to turn out - but I'm open to changes in technique as I move along.