• Universality begets complexity.
• Optimize the right thing.

• What, not how.

• You are not the typical user.
• The easier you make it for someone to do something, the more they will do it.
• Users don’t read.
• If in doubt, do the default.
• Users develop models, except they develop habits.

Make corner cases possible and no more difficult than typical cases, even if it makes typical cases cumbersome. (See “Universality begets complexity,” and “Optimize the right thing”.)

Minimum plausible affordances.