The above student is drawing from a photo-reference using the Grid-Scale process. Her basic materials are the soft leaded "Primsmacolor Pencils" and drawing paper.  Notice the vivid contrasting colors in the pencils drawing.  Because these types of pencils tend to be of a softer lead they blend better.  Plus the brand offers a broader range of colors than most other brands. 

Below are the basic notes to follow for the basic Grid-Scale process.

 The student below is drawing a self portrait using a mirror as her visual reference instead of a photograph or digital selfie type image.