Models spend a considerable amount of time putting together and maintaining portfolios, as well as scheduling and travelling to meet potential clients. A portfolio is a collection of a model’s previous work and is carried to all client meetings and bookings. Competition for jobs is strong and clients’ needs are specific, so patience and persistence are essential qualities. A model’s career depends on the preservation of his or her physical characteristics, so they need to watch their diet, exercise regularly, and get enough sleep to stay healthy and photogenic.