Choosing a massage therapist should be taken with the same amount of judgment you use choosing any medical practitioner. You need to find one that will work with you and not just on you. Asking your friends who they see is a great place to start but it's no guarantee that he or she will be the best one for you too. Personalities and techniques will vary from person to person.
Ask lots of questions. Where did they go to school and how long? Are they are licensed or certified by the state in which they practice. Typically you'll find that the longer they've been in practice, the less amount of time they spent in school (requirements change constantly). If this is the case ask about their continuing education and how thy received their certificates. The lack of current education standards is often compensated by the education they have pursued independantly.
Most importantly, get a session and pay attention to it and the results. Did they listen to you before hand and treat you accordingly? How was the flow of the session? Was it consistant throughout, did it feel like they were killing time or just not sure what they were doing? Communication is the foundation of any good session. Did they solicit feedback during and give you an assessment afterwards?
Remember, it IS all about YOU!
