Things people click.
WHAT A BUTTON MUST COMMUNICATE
That it is clickable What it does Whether it is the main action
WHAT MAKES SOMETHING LOOK CLICKABLE
Consistent styling used only for actions Sufficient contrast A shape people recognise
WHAT BREAKS IT
Styling non-clickable things the same way Styling actions differently in different places
WHAT TO LABEL BUTTONS WITH
The action they perform, specifically.
"Save changes", not "OK". "Delete account", not "Confirm".
WHY
People click without reading the surrounding text.
WHAT TO DISTINGUISH
The primary action, visually stronger Secondary actions, present but quieter Destructive actions, clearly marked
WHAT SIZE
Large enough to tap reliably on a phone.
WHAT SPACING
Enough that adjacent actions are not hit by accident.
Particularly where one is destructive.
WHAT TO PROVIDE
Feedback on press, and an indication when something is processing.
WHAT TO PREVENT
Double submission.