I would ask the following: 1) What is your experience with the types of issues I have? 2) What methods do you use? 3)Do you belong to any professional organizations? 4)What is your educational background? 5)What tools do you use? 6)What are your prices? 7)Do you have references? 8)Can I observe you at work? I would want a training professional with experience, education and accreditation. Not the accreditation you can just purchase, the type that represents a level of skill. For example, my trainer/behaviorist is a member of the IAACB (A CBC), she is a CPDT, she is on the board of the APDT, she is a Rally judge, she has numerous titles on her dog and her clients dogs and she has written two books on reactivity (she is a bit of an expert on the subject). So what of that matters if I have a dog with issues? She is a CBC which requires at least a masters degree, recommendations from several professionals including a vet, 500(I think) hours of experience and a test. She is an expert with reactivity and regularly lectures and gives seminars. In fact, her seminars count as CEUs for several organizations. She has a masters degree in human behavior. She is a R+ based trainer (a clicker trainer). This all tells me she has the experience level to deal with my problems. Additionally, the fact that she does compete in several venues and has students who title tells me she is well rounded. She is also prompt about answering my questions and always responds to me. All of that is important to me.