For the one on the far right, why not make a displacement map from it to make the cracks look more like their embedded into the face instead of just sitting in front of it? Or you could select just the cracks (Color Range selection), use that selection to copy a section of your face (exactly the shape of the cracks) and run a debossed layer effect on it, or a bevel for that matter, and then make your crack layer a little bit transparent (or a little more transparent if it already is). Then you'd really look like you were crackin' up......Or not.