I don’t believe there is a “proper” way to organize your creative writing muse.
Some authors swear by the outline. Others look at their story as a screenplay, a film unfolding behind their eyes. The characters move in linear time and imaginary spaces from expository beginning to neatly wrapped up ending. Notes are made along the way to capture scenes that flare before flaming out and dialogue exchanged before the words are lost. But the roller coaster never really jumps the tracks.
Mine does.
I plop my characters forward in time, drag them back to Chapter 2 and then fast forward to the brink of crisis constructed, confronted and resolved. Each leap polishes another facet of the jewel that is fiction.
I often write from the middle. And sometimes that changes the end.