Each time I paint with watercolors I learn something. Sometimes it is a small realization and at other times it is significant.
This painting has very few washes on it, enabling me to retain the white of the paper and move around the page rapidly. Also, the white of the paper is varied in it's character from dry brush areas to open areas. In addition, the sky where it is absent of paint at the horizon becomes part of the graded wash of blue which becomes darker in gradation the higher in the sky you go.
Finally, when I am dissatisfied with a watercolor I often turn it over and start another picture on the back. I find this works well and reliably with Arches watercolor paper.