Forms are incredibly challenging for screen reader users and people navigating via keyboard. The most common problems are missing labels (or placeholders used as labels), custom controls that are inoperable via keyboard, and hints, instructions, and validation error messages that are misplaced, hidden, or otherwise not properly associated with the relevant inputs.

• Labels
• Error messages and validation
• Submit buttons
• Fieldsets and grouping fields
• Read-only form fields

Further reading on accessibility in forms

• Form Design Patterns, Adam Silver
• Forms, US Web Design System
• The Anatomy of Accessible Forms: Best Practices, Deque
• Inclusive Inputs, Oscar Braunert
• Why the GOV.UK Design System team changed the input type for numbers