There are multiple ways to break up tasks but for myself, and with practice, the best approach I’ve found isn’t to break down a whole task at once but rather to shave off one small chunk and focus on that then revisit the task and shave off one small chunk again. I, personally, get overwhelmed if I have a long list of little steps so my task list usually looks like
Do this small thing
Come up with a new #1
It may sound silly and irrational but it works for me.