Contrast and text size
Light grey text on a white background is hard for many people to read, especially in sunlight. Check contrast from the mock-up stage.
Keyboard and screen readers
Every action must be possible with the keyboard. Meaningful images have alternative text, buttons have explicit labels.
Clear messages
An error message says what’s wrong and how to fix it. These rules are part of our method and our interface design work. See also: when to create a design system.