OK I started messing around with materials to see what to do to make a tutorial. I came up with a few but I really like this one. So to test my machine (iMac 24") I made a sample image with the material and set it to render at 6000x3200 (19 Megapixels) at 9x9pass. It took 5.5 Hours and here is what I got and the material (with included maps(All used procedural and may need adjustments for different models))
Click to view attachment
And the material itself. (Includes 2colormaps 2bumpmaps 1 preview render and the material file)
Click to view attachment
Click to view attachment
Enjoy!
Photoman