I think the line work itself is charming. Your pencil shading is all hovering around a middle tone. It might be worth doing some compositional studies to figure out some possibilities as to how to arrange the darks and lights. Stan recently did a livestream where he did some quick compositional studies as a means of exploring how to approach a piece. Here is the link: https://www.proko.com/lesson/how-to-prep-for-long-drawings/discussions