Not all plans can be implemented perfectly
Festinger's Law: Life is 10% what happens to you and 90% how you react to it.
Write down a few ideas first, and then add details later
[If Riddle had failed to frame Hagrid for the Chamber of Secrets incident fifty years ago (I've written it a little bit)]
[If Dumbledore had not chosen to show Riddle magic by pretending to burn down his wardrobe (not written at all)]
[If Lucius hadn't stuffed Riddle's diary into Ginny's book to influence Weasley (he wrote a little bit)]
[What if Harry Potter succeeded in casting the Killing Curse to kill Bellatrix Lestrange in fifth year (not written at all)]
Purpose: Show different possibilities