Sand Dunes was one of my early attempts in watercolor and one that reinforced some key learnings: (1) Use the fewest colors possible, (2) exploit the whiteness of the paper to achieve highlights, and (3) be bold with the brushstrokes. The last may be the least obvious but not less important than the other points. Slow, tentative brushstrokes inevitably are the prelude to overworked areas that spoil the painting.
I also like Sand Dunes because it was done with just two colors: yellow ochre and ultramarine blue. Simple palette, simple painting.
Sand Dunes, Watercolor on 140lb paper, 5"X7" (Not for sale)