Sigmund Freud, the first psychotherapist
My advice is this. For whatever condition or complaint you have, do your research. Find one of the most respected authorities on that particular problem in your area - an expert in, say, depression may be total rubbish at understanding Obsessive Compulsive Disorder (OCD) -, and get an appointment. He'll refer you to the right therapist for you, especially if he has a training program for them.
You may be unlucky the first time. In that case, do more research and repeat the same process I've just described, keeping in mind that one of the most important criteria for choosing a therapist, beside his orientation and method, is that he should be an expert on your particular complaint.
Forget about accreditation of a therapist through membership of a body or association. It's easy for any ignoramus to become a member.
The field of psychotherapy is a minefield. There are tons of different orientations, methods and techniques at odds with each other, a bad sign in any discipline that aspires to be based on science.
Consensus is not a sufficient condition to establish the scientific status of a discipline, but it is a necessary condition.
A great part, even the majority, of these various orientations follow fads and fashions, and are nothing more than quackery, like astrology.
There is an exception, though: cognitive-behaviour therapy (CBT) is grounded on evidence-based theories with empirical support. But here again, although it's the most reliable method in general, you have to find out if it's the best for your particular condition and importantly you have to find a therapist you can trust, by the method I described above.
Stay well clear of anything to do with psychoanalysis (whether Freudian or Kleinian), and the psychodynamic therapies derived from it.
Psychoanalysis has created an immense misery both to individuals and to society, in the latter case by totally depriving it of a grip on sexual ethics, mores and behaviour.
The complete chaos of accusations and counter allegations of rape, sex abuse of minors, sodomy, sexual harassment, groping, fondling (even allegedly occurred 40 or 50 years ago) and what not, that we are witnessing can one way or another be traced back to the kind of sexual "revolution" originally initiated by Sigmund Freud and his theory of psychoanalysis.
The so-called "sexual liberation" has produced an enormous amount of sexual slavery and sexual misery.