I usually build my forms and structure with the Claytubes brush, and I cut into the clay with the Dam_Standard brush, defining the shapes. I pull big forms out with the Move brush and use the Standard brush to detail the small forms, sculpting small details. When I'm satisfied with my shapes and structure, I use the Clay brush to clean the surface of the model and blend some areas in order to obtain a smoother look to the skin (Fig.03).
Texturing
I always start my texturing process before I create the final surface details, so in this way I'm able to create my surface details while I'm painting the texture map.
First of all I create my UV for this mesh; using UV Master in ZBrush, it is really easy to unfold them. Then I'm ready to paint on the model, using the Standard brush with RGB on and ZAdd off. I use a basic color to fill the model, then I use a dark tone for the areas where the skin is more exposed to the sun, and a light tone on the areas with less exposure to the sun. I use a warm tone on the areas where the skin is thinner and in the more sensible areas, such as nose, inside of the neck, around the eyes and mouth. In the areas like the back and top part of the head, I usually use a desaturated color (Fig.04).

Fig. 04
Now using alphas on a Standard brush, with a drag rectangle selection on it and RGB on, I'm able to paint and create the surface details at the same time. This is a really fun process to do (Fig.05).

Fig. 05