To be a professional model you have to start with a photographic portfolio.  Various photos of yourself, close up face shots, full length etc.  These can be done at any professional photographic studio.  When you have your photos professionally done, it shows your agents that you are serious about your work.  Take Jamie-Lee for instance…  She is young and

very photogenic, she loves fashion and wants to design clothing some day so she thought it’d be a good place to start with the people who would be wearing the clothing items (now that makes sense)