Ok, so I am continuing to limit my palette and I am considering the surfaces I am working on. Some have a history of marks, and others are pristine and new.
The marks I am making are affected by the texture of the surface, but also affected by the look of the surface and my reaction to my own marks in paint.
The black and white painting on cardboard formed into painting in a grid pattern, which reminded me of the way Clare Smith uses chinese practice paper (http://w0budong.wordpress.com/clare-smith/)