My projects involve an extremely rational design process.
I favor succinctness over verboseness; I distill things down to a minimum: not to oversimplify or paint issues black and white, but to reduce until only the essential vessel remains: to make ideas more universally understandable, technology more reusable.
In addition to the usual principles, I think good design:
Uses the available tools and influences new tools
Take, for example, rounded corners in the IE6 era: I think a good designer considers the entire experience: Rounded corners may provide the desired aesthetic, but they require additional code, maybe even images. Development challenges can usually be overcome, but rounded corners have user experience impacts beyond the aesthetic impact on the interface: Perhaps they increase the time to load the page, perhaps it makes the code less manageable, perhaps it means content updates aren’t as easy. I think it’s important to consider all of these factors when designing not just a screenshot, but something that has to be built, has to function, has to be maintained, has to be delivered over https and rendered on countless devices.
Now we have more extensive CSS and rounded corners don’t demand these considerations. But designers still ought to take into account the constraints — and possibilities — of the technologies and devices that realize their visions.
A good painter not only considers the emotion in a piece, they also consider the medium: the quality of the canvas or the wood panel, the paint itself.
I think a good web designer thinks not in Sketch or Figma, but in HTML and CSS. Figma or a piece of paper may well be the best tool to express those ideas. In furniture design, thinking of a shape is as important as thinking about the tools that will end up making that shape.
Design, like most other things can and ought to be measured more. Is it easier, more enjoyable or cheaper to interact with this new design? Is this new design more maintanable? More adaptable to new content?
Of course companies already A/B test elements of design, but I think what we measure should go beyond the CTA button color vs. conversion rate. Can we measure product market fit? Can we measure our users’ understand of our service? Can we measure users’ confidence in their actions?
I think every design project should start with objectives, at least some of which are concretely measurable. Often, phrasing our problem in a way that allows a measurable solution is the hardest part.
To me, design is as much about making things aesthetic as it is about making them buildable and functional. That inevitably involves identifying tradeoffs, reconciling competing priorities, and synthesizing multiple perspectives.