Most professionals engaged in the franchise industry will advise getting a referral when looking for a franchise attorney. There are other methods but when you find out about an attorney with experience
As part of due diligence you should meet with existing franchisees and ask them for lawyer referrals. Even if the attorneys are not in your area, they may be part of a network of firms with lawyers who specialize in your area.
If a referral is not available to you or you decide against hiring one you were referred to, there are plenty of other resources for finding qualified attorneys. Contact your state bar association and ask for a list of lawyers who specialize in franchise law. You may have to meet with one or two before you find the most appropriate attorney to represent you.