Greetings, and Happy Chinese New Year to those who celebrate.

I am looking for a good tutorial or book on techniques used for painting in Photoshop 5.5, where I can achieve "super photo realism" without using a 3d graphics program.

According to my mentor "Your draughtsmanship is good, but I think your problem lies in your technique. Particularly colour, shape, form and modelling. I think, as computer artwork most often looks flat (due to the nature of the medium) you really need to approach either od two extremes of painterly techniques. The first is to paint with a kind of "Super" realism in the vein of the Italian Rennaisance painters ( Leonardo etc...) or the second is to be very stylised and focus on the marks you make."

Any help would be much appreciated.