After taking several reference pictures, I chose the best ones and drew from them in order to achieve the right composition. I then added value as a way to visualize how color is going to be applied in the final version. I have yet to decide on a background design for this illo.

Once the value study is completed, I then put a large piece of tracing paper over it and copied the line work onto it...

 

... then I transferred that drawing on an illustration board, 16" x 20". Then I sealed the drawing with a coat of Fluid Matte Medium. This serves two purposes; one, it protect the original line work,and two, it serves as a medium for oil colors to be applied to.