Color above the shadows
I don't know if it will be news to you, but want to share anyway.
While drawing in Photoshop I always preferred placing color first and adding shadows, midtones and highlights next.
One friend gave me an idea to try it vise versa. Place all shadows and highlights, he said, make a monochrome picture and then place color above, it will make your work easier and faster.
I tried and it is really so.
I do not refuse using other drawing techniques, but that one is a nice addition to my knowledge collection. I take pencil drawing scetch, add shadows and highlights with brush tool (flow parameter set to 30% opacity set to 50%) and then make a few layers with color above it (with the Color option chosen for each layer), using brush again (flow and opacity 100%).
Maybe this technique will be of some use for you too.
Photo credits: Makarova Olga.