Ask what their beliefs are, what their background and training is, how they work and how much they charge. Check references before you make an appointment. Avoid working with anyone who makes you feel uncomfortable or vulnerable or tells you anything that frightens you. Similarly, avoid a psychic who makes outrageous claims that raise skepticism. A good psychic is a professional with whom you should feel comfortable and safe.
Most reputable psychics charge a flat rate per session or on an hourly basis.
This is a common scam used by unscrupulous con artists to intimidate people and gain wealth. Avoid using psychic phone services. Besides being very expensive, most of these businesses are in the business of entertainment, not counseling. Their job is to keep you on the phone as long as possible. If you find yourself consulting a psychic more often than you'd like, consider if you're addicted to the excitement and attention involved in a psychic reading.