what helps me i guess, is to think, that the client really doesn't KNOW what you're "supposed to" say. You're the expert not them. Even if you do mess up, it's a good chance they will never know. If this client treats you in any unfair way because of your height/age/whatever, that's just wrong. You wouldn't treat him badly because he's "stupid enough" to need a divorce, right? You're there to help him... if he doesn't understand that, he might just be an idiot.