top right corner: 'unrendered' colored version, just do simple shading and whatever
bottom right corner: line art, transparency lock to change the color of the line art

1) lighten (dodge) and darken (multiply): use these to emphasise shadow and highlights

2) transparency lock: duplicate the layer (top right) and use broght colors to draw highlights, turn down opacity to around 20-30%

3) classic soft: same as 2, but with colors that compliment the 'finished' drawing (top right)

#tutorial