When someone wants to brief me on a piece of copy I find the shortest route to success is to ask them for the shit version of what they want to say. I can then take that shapeless, dull, muddled piece of writing, pick the sweetcorn out of it, and make it good.
Asking for that contribution also works because it comes across as collaborative and inclusive, two things that clients seem to really appreciate. In effect, all you’re doing is asking for a more complete brief, but in the process of coming up with and writing down that crappy first draft, a client is then forced to think a bit harder about about what they do and don’t want you to say.
I think they also feel a bit exposed. They’re about to show a professional writer a piece of writing, so they tend to put a bit of effort in, giving you something at least mediocre rather than complete toilet. That means you’re already much further along the process that you would otherwise be.
A further benefit is the commitment of thought to paper (or its electronic equivalent). You then have a document to refer to if the client asks why you have included or omitted anything. If they put it in, they can’t be annoyed if you followed suit.
Of course, you don’t have to just do a good version of what they wrote. You can expand your response by asking why they have/haven’t included certain things, which again gets them to explicitly explain and justify each decision. A little chat can bring out a lot of stuff that would otherwise have remained unspoken.
You also find out where their expectations sit. That doesn’t mean you have to meet them, but it’s helpful to know what kind of thing they have in mind
From the creative’s point of view this version of the ad or copy can be also be useful as a springboard for further thinking. I recall an old boss of mine explaining how he and his partner would approach a brief: the first thing they’d do is write down the most basic functional answer (eg: a scribbled sketch of a car with a line that says ‘the new Volvo 800 is fast’). That would then be the ad any other idea would have to beat. Sure, it was dull and low on craft, but it communicated the brief clearly, so any further attempts would have to do the same, only better.
So why not give the ‘Could you write me a shit version of the ad?’ (CYWMASVOTA) technique a go sometime? You have nothing to lose but… Actually, you just have nothing to lose.