The best bet IMO for references are acquaintances that have had the same problem. Past that, the suggestions of asking other professionals is a good one. I for instance have worked with lawyers, good and bad in divorce and real estate cases over the years, and have would tend to steer a person in the right direction. If it is a real estate issue, seasoned agents and brokers have all had their experiences, good and bad, and will often share them.
As for your original question, state bar and certifications mean only that you have passed a test. Not really an indicator of competency.