My first step in this new painting was to give the 40" x 36" stretched canvas two coats of Titanium white acrylic mixed with a gloss medium.  After it dried thoroughly, I painted sections of it with Mars black:

In my next painting session, I mixed some shades of pale orange, yellow, light green and aqua.  With a brush, I painted over sections, applying the paint in a very loose, expressionist manner.  I also added some cadmium red light, diluted with water and gloss medium.  Then I used a palette knife to make two slashes of Titanium white.

When I worked on this canvas again, I realized I had lost a lot of the openness I'd created initially by filling in too much of the painting with color.  So I dipped my brush in the white paint mixture and began to selectively paint over sections in order to restore that sense of spaciousness:

In this final stage of the painting, I first felt it needed more yellow, and added it selectively.  Then I gave myself license to add whimsical lines in white and black, which had a graffiti-like effect.  When I stepped back, I was satisfied: