How do I negotiate dialogue boxes using the keyboard only?
You can cycle the dialog boxes. Also note that by default esc will choose cancel.

To enable switching via the tab key this feature go to System Preferences &#x2192; Keyboard &#x2192; Shortcuts &#x2192; Full Keyboard Access... &#x2192; All Controls



Now you can use the tab key to switch the selection:




Press Space to choose the selected button (which has a blue border around it).
Press Enter to choose the default button (the blue coloured button).
Press esc to cancel.