Felicity Evans, writing in the Smashing Magazine article When A Thousand Words Is Worth A Picture writes:

Design is itself a process of deduction. It involves a number of decisions, both conscious and unconscious. During this process, the designer dismisses some ideas as unworkable and pursues others in order to arrive at a solution.

But this process is completely opaque to the client. The client likely views the design not as the outcome of an in-depth process, but as a response to the brief, merely a visual representation of the constraints and considerations set before the designer. As the designer, part of your job is to educate the client and reveal the design process to them.

and

Good design stands up to criticism, because it is more than a matter of taste. View criticism as an opportunity to explain the reasons behind your decisions, to invite the client into the design world so that they feel like a part of the process.

You know what, just take the time to read it.