Quick Testing tips

• Check the accessibility tree inside your browser developer tools
• Check if the website is completely operable via keyboard
• Check if all inputs have a label associated
• Check if all buttons have text
• Check if all images have alt text
• Check if the document language is set correctly.
• Check your color contrasts are okay. You can manually check it via the WebAIM Contras Checker
• You can use automated tool like Lighthouse for this, which is integrated into Chrome Dev Tools.
• See also the WebAIM Million Report mentioning the most common accessibility issues. Only focusing on these would already catch a lot of issues.