Astrology is actually a science. It's based on making hypotheses, testing those hypotheses, and creating theories based on the results of testing the hypotheses. Then you test the theories. It's about observing the positions of the "planets" and "Stars" and making observations about what is going on in people's lives here on Earth.
Astrology can give insight into a subject's personality. It's a very detailed system of symbolism, mythology, archetypes, and metaphors. The subject is vast. Astrologers use their observations and calculations to uncover personality traits and likely times where certain personality traits might be more active or less active. Then the Astrologer consults with the client about their charts, transits, progressions, etc. testing all the while the validity of the conclusions made about the calculations and interpretations. It's a very soul-searching discipline. You don't have to be psychic to be an Astrologer. In fact, in true Astrology no psychic abilities are brought to the table. It's about the scientific method.
And the consultation I would do as an Astrologer is similar to what I do as a psychotherapist in that I see myself as a guide as a psychotherapist. I guide people around their psyches pointing out points of interest and difficulty. Then I guide my clients to discover their own solutions to difficulties they face. I don't interpret out of thin air. I listen, listen, listen, listen... Then I give back what I've heard from my client in a way the client may have never heard it said before. I'm basically a mirror. A good Astrologer acts as a mirror for his/her clients. And, I believe, a good psychotherapist acts as a mirror for his/her clients.