Qualifications
There are some different schools of thought on this, and it may just depend on the director or producer you talk to. Some appreciate seeing that you've attended an art or fashion school, while others just want to know that you've spent a long time working in the field (source). We guess you can't please everybody.
However, formal education and practical experience are both valuable things to have under your belt, so do what you can to get as much of both as possible.