It is always advisable to do some prior research before choosing a therapist. Initially this can be done online. Check out their qualifications and their experience and look for a therapist who explains how they approach their work, rather than someone trying to sell themselves. It is always good to see a photograph of both the therapist and if possible where they work. This may give you some intuition about whether you could work with this person. The best advice, however is to call them. A phone conversation means you can find out a little bit more about them as a therapist, but also as a person. Do they seem friendly and do are they sympathetic to your needs? Ask them whether they have experience of dealing with other clients with the similar symptoms that you have. Explain what issues you have and listen to how they respond. It is recommended you talk to several therapists before you decide which one is right for you.