Author here - I'd be keen to hear if anyone has had success with different productivity systems for breaking done the big goals into smaller items. I've had varying amounts of success with pomodoros and personal kanban - but always interested in trying out something new.
During chasing any big task you need.
a. A way to break them down in logical chunks.
b. Way to manage and execute them.
c. Way of measuring progress and tracking feedback.
d. Small chunks of iteration, where you can execute, take feedback and adapt quickly.
How you do this, is left to individual convenience.