After years of presenting deliverables to clients (designs, wireframes, websites, etc . . . ) we have learned that we will never be able to predict a client’s reaction with total confidence. This is not only because design is subjective, but because we may have different visions of the final product. Even if we took the time to understand our clients goals and vision, it is impossible for us to be able to predict the exact product they have in mind.
Since we aren't going to nail the design 100% on the first try, it's important that we design quickly and iteratively - together with our client. The sooner we can bring an idea to reality, the sooner our client can bring reality to our idea.
It's because of this that we've started adopting lo-fi (i.e. napkin-sketch-quality work) design techniques in our very first interactions with clients. Once an idea is on paper (or whiteboard), we can quickly iterate designs, working together while referencing the same product.
When everyone is working together, it's easy to focus on the product and ask why, not just what:
"What colors did we choose for the palette?"
"What layout choices did we make?"
"What content did we use for the headline?"
But real breakthroughs occur when we ask questions such as:
"Why did you think that particular color made sense?"
"Why did you want the buttons to appear so large?"
"Why did you lead with that particular message?"
It's only when we ask 'why' that we really understand whether we are designing for ourselves, our client or our client's audience. It's only when we're designing for our client's audience that we truly succeed.