using India Ink

start by blocking in the rough shape, considering the dark/shadow and the light; using diluted india ink


after letting the first layer dry a bit, go over it again focusing on a smaller part of the shadow, adding the cast shadow



using undiluted india ink, add the darkest areas of shadow



while the last layer is still wet, use a wet brush with the diluted india ink and work the darker mid-tone gray areas



if things are getting too dark, you can use a piece of paper towel to pull off some of the ink in the middle gray areas