A classic method of toning the canvas, board or support that we work on is called “imprimatura” – glazing a middle value. Depending on the effect and painting style that we work in, we can alter the texture of the support before glazing with gesso or acrylic medium using brush marks and a palette knife. Some painters like to create a smooth surface by sanding.
Painting a middle value sets the stage for thinking about keeping the values limited to darks, middle values and lights. This simplified approach helps us see the dark values in general linked shapes.
Try blocking in the dark values first on the toned canvas. Often these darker values include the shadow shapes, and keeping them as glazes can prevent them from becoming muddy. The “darks” of your painting can be mixed from complementary colors, hues that are “opposite” to one another. This produces color harmony, working from a limited palette.