We were on the receiving end of an angry review of a speech we'd co-written. The client rattled off problem after problem, even phrase after phrase, complaining about what he thought was wrong. I steeled myself for an all-nighter.
"Nah, I got this. Half-hour, tops. Go home," said my writing partner, a former White House speechwriter with years of experience on me.
"But he just gave us 20 minutes of complaints!" I said.
"And I wrote down every one," said my partner. "He told us words and stories he didn't like, he wants a new opening and closing, and he didn't like the quote in the middle. This is mechanical. I can fix it in a half-hour."
And he did. And the client called the next day to praise us to the skies.
When your writing client complains, write down the specifics. When the client is vague, press them for specifics. Then take out exactly what they don't like and put in something else. Usually they'll tell you down to the word -- if you're paying attention.
Don't spend hours trying to feel your way through it. If you listen and ask questions, most of the time you can get what you need to make your client happy. Make a list of changes and check 'em off. This works.