Key To a Succesful Tutoring Session

What do I believe to be the key to a successful tutoring session? Well for one even if a student doesn't walk out of a tutoring session with a complete paper that doesn't really mean the session was unsuccessful now if the student walks out of there still not understanding the assignment they have to do or if they don't have any ideas then that would be an unsuccessful session in my opinion. I believe what can be a successful tutor session is when a student and tutor understand each other. If tutor or the tutee can't understand what the other is talking about then that is an unsuccessful tutor session in my opinion.