I have hree types of process, but for now I am using almost one, sensitive pressure, hard edge basic brush, and black color (I am using only basic brush for now), I start whit shades, tracing it and then going to light whit lighter strokes. After that I refine whit color pick and transition. I ll even do the opposite, refining light whit same brush and white color.
The other two ways are made refining the hard edge whit soft brush and a third method done whit a splash of midtone adjusted whit white strokes as light.
Now I feel I need to study more about values to know how decide which value choose over the grayscale (for now I go from total black to total white)