Messaging is vital and there are messages in what you say, but also messages in how you say it.
Here are some messages to say directly: Communicate you know what they need from you, communicate you have an idea of what your competition is and how they may be strong. These demonstrate you have prepared and are willing to do your homework. Finally, ask the interviewer, “How are you on time?” This will let him know you are thinking of him and you are being courteous and respectful of his most valuable resource: Time.
Here are some messages to say indirectly. Communicate them by the way you speak: Respect for his time, by listening and not rushing. Ask if you have answered their questions. Five minutes before the time is up, say, “I see we have 5 minutes left. I’d like to add one more comment and then please let me know what I may have missed.” Communicate through your courtesy that they are in charge, that you listen, that you respect them. Communicate humility by asking well informed questions, then listen to the answer. Ask permission to take notes, saying, “May I write that down?”
Finally, project calm. In any high stakes transaction, the sophisticated salesman removes pressure as you both approach the decision point. By doing this you communicate confidence and that you are master of your emotions.