Concept art - Unique method

In my opinion this is a very interesting method to creating concept art. At first he puts a random 'doodley' type sketch to create a unique shape for the model to be based upon. Then goes into more depth outlining it and adding detail. He also uses his past mistakes to create more in-depth detailing  which is a very interesting method of creating. The highlights on the final piece really brings it to life adding definition to all the parts of the models body, which also amplifies the shadow creating a very dramatic effect.