MY APOLOGIES FOR THE LARGE FILE. ♥
I see a lot of 'cracked' tutorials that kind of just seem like stamping brushes over facial features and not taking as much time to show that there is depth to the cracks.
Being a fan of the effect, I thought I'd explain it through the process of making one of my deviations, Broken Girl.Original Deviation: [link]
Stock model: [link]
Concrete used for under cracks: [link]
Concrete used for wall: [link]Crack brushes: