Medical competence is the overriding factor to consider. Listens, which should not be confused with good hearing. Considers your description at least as much as test results. Approaches problems based on a balance between facts, feelings and intuition. Possesses a broad and level knowledge of medicine, not just a narrow specialized focus.
Most doctors are very busy.
Their time with you is usually very brief. Putting together a list of questions you want to ask the doctor. Prioritizing your questions and concerns, asking the most important ones first in case you don't get to ask all of them. Discuss your principal complaints first. Avoid getting off the point.