Good design, Dieter Rams
Here’s some “rules” for good design, from the timeless guru of buttons, Dieter Rams. <http://www.vitsoe.com/en/gb/about/gooddesign>
These are all well and good - if anything, they tend toward the utilitarian. I like to have a little more room for “beauty” and “elegance”, but I take his point about these being very subjective values. And the most important rule must be remembered: All rules are meant to be broken.
(credit to @gruber for the original link)