I'm copying and expanding on an answer I posted on Quora, the question being, "How do you teach a non-designer to effectively critique a design?" When working

I'm copying and expanding on an answer I posted on Quora, the question being, "How do you teach a non-designer to effectively critique a design?" When working with an "amateur" client who doesn't understand much about design, it's helpful to prepare a design brief before beginning any work. This is a written description of the goals of the project. When you meet with the client initially, they will probably have a lot of vague or even contradictory ideas. It's your job to sort through the ideas and write up a design brief. Show it to the client, and either get them to sign off, or revise as needed. Going forward, when reviewing comps, try to steer the conversation back to the goals you set in the brief, and discuss how well the comps are meeting the goals (or not). Try to avoid letting them offer solutions like "make this font bigger" or "make it blue." This transforms you from a designer into a computer monkey. Clients who treat you this way are disrespectful at best, and are best avoided entirely. To append to that answer, your insight about "only YOU really know your application" is analagous to the concept of the "design brief." Design is not only how it looks, but how it works. The brief should explain this, so that when working with a designer who is focused on the visual, you can always bring them back to the brief, and ask how their visual changes support the brief.