Our first drafts can sometimes end up shorter than we would like them to be. This is often due to missing details, a need for better descriptions, areas where we did more telling than showing… We can’t always expect everything to come to mind when we need it to.
It can be difficult to tie up all your loose threads if you can't remember them. Outlining can help you pace your ending and keep the event order straight as each unfolds. Think about your climax's impact and how everything needs to come together for a powerful ending.