/ic/ - Artwork/Critique

I like the information in loomis' head and hands book but I feel like he never really tells the reader what exercises to do? Do I copy him? Do i try make my own version? A lot of his drawings appear in the book without much text to describe the details, like these skulls. He kinda just talks about them in general but never goes really in depth on how to draw it. Of course this information can be inferred by looking at the picture, such as the shape and general size of eye sockets, but I feel like text would be really helpful.