The job duties of a freelance book illustrator are to create illustrations for books and other publications. As a freelancer, you create art for different clients on a contract basis. If you work on children’s books or other narrative content, you design images that depict the written story in the book. Your responsibilities and image style vary depending on the needs of each client. Clients often ask for a sketch of your plan before you start illustrating each picture. As a freelance illustrator, clients expect you to complete illustrations by a predetermined deadline.