Another direction to explore is following or echoing the contours of the shapes. Start with one color, and paint the lines of the negative spaces. Then select another color and paint another line alongside the red ones, then do it agian with another color.
The photo shows this, starting with red, then an orange and yellows. (The negative space lines from the previous photo have been changed from black to red.) The painting doesn't look like much at the moment, but remember, this is just a way into an abstract painting. It isn't the final painting, it's a starting point. You work with it, pursuing it, seeing where it takes you -- in this instance it was to this.
