1. Ask someone for a referral from someone that has been in therapy (or can point you to someone who has) and has seen someone who was helpful to them. Try to get up the courage to ask them if they know of a good therapist. Ask them how they were helpful and see if that resonates somewhat with what you are looking for.
2. Do not be afraid to shop around. Therapy is a big investment of your time, money and effort. It can be discouraging to not get anywhere with someone or get nowhere and have to start over, or perhaps worse, give up on seeking help/change altogether. If you make this decision too quickly, you might ask yourself if this is a part of a pattern for you that sets you back: not thinking through your decisions before making big life decisions, etc. Visit two or three (or more) therapists to compare your experience. Many therapists are willing to provide a free initial consultation to help you along with the process, although some might ask you to pay later only if you decide to continue with them.
3. Good therapy, convenient location, whether they are on your insurance plan, etc., DO NOT always go hand-in-hand. If you are able to not restrict yourself in these ways, the more limits you place upon the possibilities for help, you run the risk of compromising your experience. However, this does not mean that you will not have a good experience if you need to use your insurance, can only drive a limited distance, etc. Just try to not start out with too many limitations, or assume all therapists are the same. This is not a statement so much as therapists being better than other, but more aimed at finding the better or best therapist for you--the best "fit." Place as much value on yourself and your life that you can. If you do not have to cut too many corners, this gives you more chances and potential to find the best fit for you.
4. Beware of therapists who: a) Seem to claim to be an expert in everything; b) specialize in a particular diagnosis or types of diagnoses. Diagnoses say very little about the person. There is no "one size fits all" approach; c) therapists who have not been to therapy/are still not in there own therapy. While some people can think that a therapist should have mastery over their lives in order to help people, growth is an ongoing process as life's challenges bring to each of us. Has your therapist been to their own therapy? Are they currently in therapy? It has been said that a therapist who has not/is not in therapy can be like a religious minister who is not sure (s)he believes in God; d) Also watch out for therapists who make guarantees or promises. While this may seem desirable, the ability to hope, to feel that resolution of life's challenges are possible is probably more realistic than promises.
5. Qualifications. Are they trained and have a degree from a graduate program in psychology, counseling, social work or related behavioral science. Are they licensed in their field of specialty? Next, consider how they might qualify for you. Would you prefer to see a man or a woman? What age seems like they might relate more to your situation?
6. Meeting with a prospective therapist. How does it feel to sit with them and talk? Do they feel realistic to you? Are they able to flexible and learn about your situation or do they seem to steer you towards their perspective (seem to have already formulated what is needed)? Do you feel heard by them? Do you feel, as much as is possible for a first meeting, that the two of you could develop a mutual and working understanding of your issue/problem and how it will be worked on? How flexible are they...if they mistake what you are saying, can they flexibly adapt to what you are saying (e.g., get back on track with you)? In other words, can they accept feedback and admit mistakes if they make one? Do you feel taken seriously, that your life situation and concerns matter to the therapist? Has this prospective therapist worked with the kind of issues you are hoping to address? What is your therapist's belief about therapy and how it works. What is their "theoretical orientation?" For more on what a theoretical orientation, you can start with this article: Demystifying Therapy: What's a Theoretical Orientation? It is important to begin to explore what approach to therapy feels like it might be right to you, or at least begin to explore this.
This list, while not complete or comprehensive, should give you a fair start in the process of finding the right therapist for you.