Here are my early steps in a still life painting. . (No, I don't copy the photo. I work from direct observation when doing this sort of work. I'm just showing the source) I do a quick figuring out on canvas with charcoal, then lose that when I put a wash of a neutral oil paint color down and wipe out the lights and intensify the darks. Then the first color marks, a little heavy handed- but I can go for more subtlety later. The triptych is 3 wood panels of 3"x4" and the larger composition is 8" square canvas.