I used to fly for one client who, if I said something along the lines of, "I don't think we should do this today," would ask the obvious question, "Why?"
"I'm not happy with it," replied I.
Immediately, hands up, "If you're not happy with it, then neither am I. We can do it tomorrow," he'd say. Fantastic. There's not many clients like that.
The trick was figuring out how many times a week I could get away with it.
In my very dim and distant past, I once read the art of diplomacy defined as being able to tell a person to go to Hell in such a way that he would look forward to the journey.