ArtBistro

I don't know if you use these colors or ones similar to them but here is my standard palette : Cadmium scarlet (warm red), French Ultramarine, Cerulean Blue Hue, Permanent Alizarin Crimson, Soft Mixing White, Titanium White, Dioxazine purple, Phthalo Green (a little drop is of this color makes a world of difference), Burnt Sienna , Raw Sienna, and Cadmium yellow. 

With these colors (or even less) I am able to mix a multitude of different colors. I don't typically use the "typical" fleshy colors. I use a lot more blues and greens in my work, but here is how I usually paint. 

Just remember, when greying down color to simulate shadows, you are not really adding shadows...you are simply adjusting the hue to cause viewers to believe what they are seeing is a shadow. 

Also, when light source is cool the shadow will be warm and vice versa.

For example, I usually start with two bases; one for skin tone in light and one for shadow areas. The choice depends on the coloring of the model and the light source (warm or cool light). For example, if I'm painting a blonde in cool light I mix a light base from the cadmium scarlet and cadmium yellow - cooling it with violet to the correct shade (because they are opposites and because when you mix them, they become more natural together). You can also make a shadow base using, french ultramarine graying it down with white if you like. 

These are my basics.  I almost never use black right out of the tub. I always mix Ultramarine blue and burnt umber with a touch of raw sienna to give shadow effects. It's almost amazing how much of a difference you see, especially if you want black to be warm or cool. 

Hope it helps.

=)

 This is coming from an oil painting group. A lot depends on your approach to oil painting. Are you using glazing, dry brush in upper layers, flat color with blending, visible brush strokes, variety of thickness, start out with large areas of color and building up to smaller strokes, single sitting, multiple sittings, a combination of all of these? Etc. Some people have a process they have worked out. Oil is a flexible medium and there is no one right approach. You do need to be aware of some of the craft involved so the paintings are strong from a view of durability. 

Some people tend to keep shadow areas thinner. You can sneak up to the final shadow area color-terra verte could be a starting point.I often see subtle green tones in shadow areas that are enlivened by other warmer tones. Shadows tend to be cool colors on the figure. Of course this idea is easily broken to good effect. There are a large variety of skin tones from one individual to another.

There is a topic on painting flesh in this group. There are some good figure painters on artbistro, some work from models, some from photos. They all have different approaches. I would also look at master painters. When I look at a painting, I usually try to figure out how they did it. I like your work.