When I paint anything with a face, I always paint the eyes last. We have a natural instinct to look a person or living creature directly in the eyes, and because of this can miss important details or colors because of being distracted by them. I also find that when everything else is where it is suppose to be, the placement and reflections seem to show themselves.
Before I focus on details, highlights or shadows, I just focus on shape and color and anatomy. I know the claws are suppose to be different because ones a crusher claw, (I’m surprised by how many New Englanders think this is a mistake!). The color on the top of the shell is freckled in lighter color. I start adding shape to the broad shapes using different reds and magenta’s rather than blacks or browns.
I think of it as if I took a camera and started with it out of focus then slowly dial it in layer by layer.
When creating shadows, I do not use black that often. I take the color in that area, and add its opposite color to create a contrast. By dulling the original color it gives a better illusion of an absence of light. Black is made of all colors so it reflects all those colors when the red lightens it, and if an object is red its not putting off blue shadows. Your eyes and brain are trained to pick up on this. I have a blog about tricks to understanding color and color opposites here.
I love lemon on my lobster! Can’t have a lobster dinner without lemons. When I paint lemons I want all but the peel itself to be transparent. I use a cheap khaki color to preserve the transparency. I use khaki instead of white, ivory or yellow because I know the wood color behind it has a play in the actual color we see. In fact the only part of the lemon that has yellow in it is the peel line on the outside. The rest is just an illusion. To make this object look as if it on a surface and not floating, there are light shadows that I painted underneath.