When you communicate with a client, you likely have on your "game face" and project a high degree of professionalism. Do you do the same with internal colleagues? Whether you are talking with your assistant, your boss, or the CEO of a client, it pays to be thoughtful and articulate every time. When you ask a question, make sure it's a smart one. When you present an analysis, spend a few minutes thinking ahead about your key message, supporting details, and follow-up or action items. This shows your team that you have respect for them, and allows you to continually practice so you're ready for the real thing. It also shows those paying attention that you are smart, competent, and client ready.
Source: from "Your Boss is Your Client (& Your Colleagues Are Too)" by Jodi Glickman