What does the reader want to happen? How much of that do I want to show the reader?
I think that part of creating an emotionally satisfying ending is to give the reader a lot of what they want to happen. That doesn't mean I have to do it in a straightforward way. I can throw in some unexpected twists. Since I write MG, I think my readers do want a mostly happy ending. They want the heroine come out as a winner and the bad guys get punished. The main character should mostly get what she wants.
Thinking this way also shows me which scenes will be most important to the reader. Those are the scenes I don't want to sum up in a few lines or rush through. I can create suspense and stretch out those scenes to build up more of an emotional impact.
What is the simplest ending that will work for my story?
I want to wrap up most of the the loose ends so the reader can feel the problems are resolved. Even though I'm throwing in some unexpected twists, I think the book will be strongest if it ends without too much complexity.
After all, if the route to the final scene is too convoluted, the reader will get caught up in following the thought process instead of the emotional experience.
What questions do you ask yourself when you're revising the ending?