This document discusses best practices for client managers based on the experiences of several professionals. It outlines four main rules: 1) Set expectations early and often to avoid misunderstandings; 2) Communicate frequently with clients to address concerns before they become problems; 3) Pick up the phone to have more emphatic and honest conversations; 4) Do what you say you will do and communicate your actions clearly to build trust. Following these guidelines can help client managers avoid providing a bad experience and becoming a "client manager from hell."