Be passionate and articulate, but most of all have a knowledge of the lingo and the basic parameters that would be involved with doing these deals. Check out the company's website so you can see what they currently offer. Contact your local Economic Development Center, to get their feedback on area licensing consultants and experts. Seek out some legal advice from a apparel licensing firms (Google that phrase along with your county and state and see what pops up).
Another suggestion : check out the apparel industry's main trade publications and Entrepreneur.com for more articles on licensing. Getting input from these various resources can help you navigate through the many options and pitfalls you are sure to encounter along the way.
Best of luck in your endeavors!