I began with a wash of cerulean blue. This blue is very light, and it takes a lot of pigment to cover a given area (this may be a function of the particular brand of watercolor, though). I applied masking frisket on top of that layer and added a flourish with a can of compressed air.
After drying, I re-painted the entire sheet with dark blues. After removing the frisket, I touched up the cerulean traces with different colors.
This piece evokes the images of dragons for me.