If you choose, you can do some preparation work before starting with a therapist by familiarizing yourself in the methods that he or she uses. I have listed some resources here about how I work. Learning about my methods will shorten the time we work face-to-face easily by a few sessions. If you find my methods to be reasonable or you are at least curious about them, it increases the chance that we are a good match.
After you have established a good working relationship with your therapist, experiment with the frequency or the length of therapy sessions. Weekly 45- or 60-minute sessions are what nearly all therapists in private practice offer, but see if you can have longer sessions but less often.
Most importantly, choose your therapist well. While credentials give some level of quality assurance, what matters is your personal preference and comfort. Trust your gut and work only with someone you feel good about. If you like your therapist but don’t see some results within a couple of months, be sure to discuss it with her/him.
Lastly, some therapists offer a “sliding scale” which is a lowered fee based on your financial situation. Call around and ask. Community mental health clinics often have therapists in training who will see clients for a low fee and they can be just as effective as a seasoned therapist.