Couples therapists are people just like everyone else. They vary, have differences, have different training and experience. Below is a list of recommendations in regard to training and experience:
1. Pick an experienced couples therapist, one that has been seeing many couples for many years. Being an experienced therapist and being an experienced couples therapist are two different things. Almost all therapists have seen some couples; most have only seen a few in their careers. Often, the better couples therapist is the the one that has more extensive couples work.
2. Pick the better trained couples therapist, the one that has more training. Ph.D.s have more training than Masters level therapists in their schooling. So they, Ph.D.s, usually have the edge in some ways coming right out of school. However, many Ph.D.s have little or no couples training in school! But how much training the therapist has after getting out of school matters more than the degree. So much is learned by practicing in the real world. So you might ask about how much training the couples therapist has after getting out of school and, if you care, how much couples training while she/he was in school.
3. In my experience, which type of therapy the couples counselor practices is really not so important. You want someone that knows what he or she is doing, not someone who knows a certain type of therapy better than someone else. Research has shown that experienced therapists are more like each other than they are like novices (newbies) in their fields. That means that experienced therapists over time have gravitated towards using techniques and practices that work for experienced couples therapists, which the novices won’t have learned yet.
4. The gender of the couples therapist does not matter, unless one or both of you have a preference—then you might choose to go with your preference.
5. The older more experienced therapist might be better than the younger inexperienced one. Sometimes that will not be true. But the older and experienced therapist often is that, older and more experienced, and will know more about helping you and your partner.
Disclaimer: I am an older and more experienced couples therapist and a Ph.D. psychologist. My biases will have shown through in this writing, but everything I have written has truth in it. You may want to search for what younger and less experienced couples counselors have to say in comparison.