When writing a long story, it can be beneficial to outline each plot point as you edit it. Also, there is a feature in Word that can allow you to have the story read to you, change the spacing to allow for easier editing, etc. It is mostly beneficial to see grammar mistakes, or if you like writing poetry, but syllables elude you. There are two types of writers:
Outliners and Pantsers
The outliner will create a concept map of characters or an outline to guide them in their writing. So, a character based outliner might take a character:
Jess
Then, create branches from there in a concept map.
A plot-based outliner might create a timeline.
Both of these tools are helpful to keep you organized.
Pantsers generally "become the story". Thus, they do not "outline". They have an idea of where it starts and where it ends, but let the story or characters guide them. These people will tell you that "you just can't outline a story". They believe that if you fully immerse yourself in the story or characters such mistakes won't be made.
I hope this helps you! Please, don't hesitate to contact me for more questions! :)