Automated accessibility tools are useful, but they cannot understand every experience. They can find missing attributes, contrast problems, and structural issues, while manual testing reveals whether a person can actually navigate and complete tasks comfortably.
Start with the keyboard. Move through navigation, forms, filters, dialogs, accordions, and buttons without a mouse. Focus should remain visible, the order should make sense, and a modal should return focus to the control that opened it when it closes.
Then test content and semantics. Check heading levels, labels, alternative text, error messages, link purpose, and dynamic status updates. A screen reader review can reveal when visual context has not been communicated in the DOM.
Accessibility is a continuous quality practice. Testing early and after every major interaction change is more reliable than attempting a large repair at the end of development.
Document the issues you find with the affected page, user journey, expected behavior, and priority. Clear notes help developers fix the underlying pattern instead of patching only one visible instance.