Did another process demo in painter.
First - start with a value study. Block in your shapes, considering your light source and your focal point. It is the apple in this image.
Next is the intitial color wash in digital watercolor (simple water brush). I like the digital watercolor because it allows me to paint from dark to light - and because it allows me to tint my value study.
Next,I dry the digital water and then use a custom airbrush to paint opaquely over the image. I push the highlights, color saturation, tints and shades at this stage - trying to keep the most saturated area in the middle values on the light side.
Adding more detail with the opaque mediums. A cool wash over the entire image in digital watercolor is then applied. This is done to unify the shadow areas. Next is to pull back the warm/light side by using digital watercolor set at white.
This could still be taken much farther. It's just a matter of detail now.