Sight size method

So the next step after you complete first three Bargue drawings, is to do "Charcoal cast drawings"

This is done using "Sight size method"on a canson sheet using different grades of charcoal sticks.

It really helped me in training my eyes to see the values and planes. 

The drawing board had to be placed next to the cast and I had to accurately render the drawing with the values that I see on the cast. It is completely different from the Bargue plates, but for this, one has to understand and analyze what you see and what you draw, to create an illusion of a 3D form on paper.

Here is my first charcoal cast:

My second charcoal cast:

The cast(on the right) with my charcoal study(on left)