I had already written the whole first draft when I realized I was missing a few things. In order to get them right, I wrote an outline because I was just fed-up with missing things. (Really, I wrote a few outlines). I wrote out every major scene in each chapter, and what the MCs find out in that chapter, or what they have to find out if I hadn't already included it, all in different colors. I love color coding! I also included keywords like INCITING INCIDENT, ESCALATING TENSION, RESTING POINT, THE BLACK MOMENT, TURNAROUND etc. This helped me sort out where specific points of tension of the story would go where. I think this also helped me with pacing, to make sure the story was moving forward.
I think outlining really saved my book. It was a jumbled mess before I revised it using an outline. It really allows you, as the writer, to see all the arcs of the all the plot threads. I also used it to sort out when and where the MCs find out specific pieces of information. Before outlining, the MCs would find out massive amounts of plot information at a time. Then I realized I could let the information progress through the story.
I'm still in the middle of revising using my outline. If I had used one in the beginning, I really could have saved myself a lot of time and work, and be done revising, which I feel like I've been doing foreverrrrrr. But it's all part of the process, right? Better to get things right now, rather than start querying too early.
How do you feel about outlines? Do you use them? Why or why not?