Watercolors striving for technical mastery frequently picture flowers, lace, mirrored surfaces and glass. They tend to be very popular with the public and sell for high prices. The subjects are treated in a clinical, formalistic way. Most beginners want to paint this way - BUT the technical mastery approach requires skills usually achieved only after intensive work.

They are usually carfeully planned in advance, or even sketched before painting - erasers [link] that take graphite off the substrate without affecting the watercolor are available. The sketched lines remain here. [view]

Sharp highs / edges often indicate the use  of frisket [link] to resist washes. In this example [view], I'm pretty sure Mr. Gill used wet on dry technique instead, which requires fantastic control.