Apply basic shadows
I set a new layer to Overlay and use the Gradient tool to establish my basic lighting. Once I’m happy with this, I create a new layer and start lightly airbrushing in shadowed areas and highlight brighter areas, such as the nose, mouth and eyes. I build over this a couple of times until I’m happy with the overall look that I’m developing.
I use an assortment of textured brushes to add a bit more dimension to my work. Some of my favourite brushes for this are from Kyle T Webster’s ULTIMATE MegaPack, which you can buy at I want to play around with gritty brushes so I switch between my layers and keep building texture and tone as I go.