There is no one answer to this question as the job of a fashion illustrator can vary greatly depending on the type of clothing or accessory that is being illustrated. However, some common duties for fashion illustrators may include creating illustrations that accompany fashion articles, designing and illustrating advertisements, or working on illustrations for books and other publications. In addition to their creative work, fashion illustrators may also need to be able to communicate effectively with clients and colleagues, as well as have a good eye for detail.