Contrast and Readability
The WCAG 4.5:1 contrast ratio requirement isn't arbitrary. It reflects the actual visual needs of users with low vision or colour blindness — and it turns out that high contrast also makes products easier to read for everyone in bright sunlight or on budget screens.
Start by running your existing colour palette through a contrast checker. Most design systems have at least a few pairings that fail at body text sizes. Fixing these is usually a two-hour task with outsized impact.
Keyboard Navigation
Every interactive element on your product should be reachable and operable by keyboard alone. This is a requirement for users with motor disabilities, and it's also exactly what screen readers use to navigate your interface.
The two most common failures are invisible focus states (elements that are keyboard-reachable but don't visually indicate focus) and tab traps (modals that steal focus and never release it).
Plain Language
Accessibility is not just visual. Cognitive accessibility — writing in plain, simple language — matters enormously for users with cognitive disabilities, non-native speakers, and anyone reading quickly.
A useful test: read your error messages and onboarding copy aloud. If they sound like legal disclaimers or engineering tickets, rewrite them.
Closing
Accessible design is better design. The constraints it imposes — clarity, contrast, navigability — are the same constraints that produce great interfaces for everyone. Build for the edges and the middle takes care of itself.