It really depends on who and what you are dealing with and how you should respond.
Always be firm and don't let him step all over you.
If he is irrational - come back at him with a rational arguement.
Scream louder if you must.
Let him scream and yell and when he is quiet just gaze into his eyes, when he asks,"what?" - say, "Oh, I just wanted to make sure you were finished." - Then get up and excuse yourself to do something and make him wait until you are calm enough to deal with him.
When the clients that I handle most at work get out of control - I listen and then I pause for a moment so I know I have their attention. I will either try and find out what the bottom line is to them being happy is or I simply manipulate the conversation and try and catch them in a snag or conflict to gain control of the conversation.
Learn not to be afraid of telling them they may not be correct.
Apologize when you are incorrect but don't get insecure because of it.
Try and say negative things in a postive way - like you are not correct opposed to you are wrong.
When all else fails and you know nothing about them do as others have said and find some sort of common ground and agree with their view points.
I did this yesterday with a co-op board president that was just trying to make herself THAT much more important in the prelimnary process than she really is all the while knowing that she will make or break a renovation approval for me. I apppealed to her extreme dislike for men - and I can actually how a calm mature conversation with her now.
How sad is that?
Also know that there are people that are just miserable bastards and they is nothing you can do but have many lunch meetings and see if food or food and drink makes them more human.
OH..
GOOD LUCK!!!
Please Scroll Down to See Forums Below 
