I have not yet completed a Spilling Over page, but I do have another installment about painting with watercolor and didn't want to to go missing on this fabulous blog.
You will see that when you don't want a wet-on-wet look, where one color or pool of paint flows magically into another, you will want to keep the areas you are painting separate. They appear almost as islands onto themselves. You can then either dry them with a heat gun, or allow them to dry on their own and paint the remaining areas later. Watercolor and gouache is a magical paint, and requires some finesse. But the beauty of it is luminescent.