1. Do we need the button to be disabled by default (e.g., item is unavailable)?
2. If not, can we keep it enabled and validate user input on submit?
3. If not, can we rely on default values to keep the button enabled?
4. When should the button become disabled (e.g., prevent double bookings)?
5. Do we want to gray out any part of the interface along with the disabled button?
6. Do we want to use a skeleton screen animation as well as the disabled button?
7. Do we want to use a loading spinner for the UI to indicate that the system is busy?
8. Do we want to use a progress indicator on the button to indicate progress?
9. Should the wording on the button be different when it's disabled?
10. Does it have sufficient color contrast in the disabled state?
11. Do we want to add a note under the button explaining why it is disabled?
12. Do we want to use a tooltip explaining why the button is disabled?
13. Do we keep the disabled button focusable?
14. What happens when a user hovers or taps on the disabled button?
15. What happens when a user tries to activate or focus on the disabled button?
16. Do we change the cursor to not-allowed to indicate that the action isn't allowed?
17. Do we prevent the click via JavaScript by using aria-disabled?
18. Do we use ARIA live regions to announce dynamic content?
19. Do we avoid pointer-events: none as it doesn't prevent focus/keyboard navigation?
20. Do we guide users towards error messages when they tap/click/tab to the disabled button?
21. When do we enable a disabled button?
22. Can we add a link that sends all user input to support if they are locked out?
23. In that case, do we ask users for their consent to be contacted?
24. Do we use inline validation (positive or negative)?
25. When and how do we show error messages?
26. Do we include an option to continue even if inline validation fails?
27. Do we need to update the state of the button after every user input?
28. How will the button change while updating its state?
29. Do we change the label of the button ('Updating...') while it's updating?
30. Do we change the colors of the button while it's updating?
31. Do we want to add a loading spinner while the button is updating?
32. Should we stop listening to click/tap after the first click/tap?
33. Do we not stop listening to click/tap for undo buttons and steppers?
34. Do we track how many people who can't proceed and abandon the flow altogether?
35. If applicable, can we test if a design without disabled buttons performs better?