I used a full sheet of Arches paper for this painting. Here I have reserved the whites with resist in preparation for the first wet in wet washes.
I had a great time sloshing in all the juicy colors with a 2" flat brush; the resist acts like a dam keeping the colors from mixing where I don't want them to.
I have laid in a second wash of darker values, still using the resist to help isolate colors from each other.