When interviewing a prospective tutor, parents should ask about the tutor's skills and experience, and find out if the tutor truly enjoys teaching. When the tutor feels enthusiastic about the subject, and communicates well, the student has an opportunity to learn to enjoy the subject too.
I recommend for parents to observe the first lesson to see the tutor's skills in action, and watch/listen carefully to future lessons when possible, to make sure the tutor has an encouraging, supportive attitude at all times. (Tutors should welcome and respond positively to the child's questions, and NEVER make the child feel "stupid," no matter what.) It is most important to have a safe and quiet place for studying, without distractions. I like to find a quiet table at a library, and work with students there. I welcome suggestions from parents, and I am always looking for ways to improve my teaching skills.