The general rule in watercolor is to start lighter and work your way darker. With the exception noted in the last step, this is my general pattern. It is better to add dark detail over pre existing washes so that your details do not become smeared by subsequent brush strokes. I was interested to discover the dark patch at the back of the head. I had never noticed that before making this detailed field drawing. It was fun to look back over old illustrations and see how I had overlooked this subtle detail.