One of the most important things when interviewing for any job, even a stock position at a retail store, is to dress like you mean business.
My interview process started by having a friend who worked there give me an introduction. Telling the manager who I was, what I was like, and explaining my qualifications. Then I described myself in more detail, told her my ambitions, and explained my reason for wanting to work at The Gap. She asked me various questions about myself to follow up, alot of personal questions to gauge what kind of person I was. Honest answers seem to work best.