I am now imparting to you the deepest, darkest secrets of the obsessive plotter.
The best part of a spreadsheet is that it can record anything you want. If you want to see whether your subplots all get equal screentime, you can use a spreadsheet. If you want to see whether you forgot to describe certain locations, you can use a spreadsheet. And so on.
This is roughly how I use spreadsheets, although they are, as I said, infinitely customisable.
The first column is for the parts of a three-act structure. Act one (introduction to the characters, the world and the story, inciting incident occurs, and things start going wrong); act one turning point (everything goes dramatically wrong leading to a crisis); act two (in trying to fix the previous crisis, the protagonist makes things worse); act two turning point (everything goes dramatically wrong leading to an even worse crisis); black moment (lowest possible moment at which all seems lost for the protagonist); act three (the protagonist is now moving inexorably toward a confrontation with the antagonist that seems impossible to win); climax (somehow the protagonist beats the antagonist); resolution (tying up of loose ends).
The second column is for chapters, or scenes, depending on how detailed you want to get. Each is assigned to the appropriate part of the structure. For example, if chapter twenty is the black moment, you move across from the black moment and enter chapter twenty. By this stage you can see approximately how many chapters are devoted to each act. If act one is thirty chapters long while acts two and three are both five chapters, you probably have too much setup in act one.
The third column is for the main plot. In our black moment, chapter twenty, the protagonist hits their lowest point and it seems impossible for them to continue. Let's say that they've, oops, accidentally nuked their home planet. That's what you enter across from chapter twenty. Here you're making sure that you have all the relevant parts of the structure. If you're missing an act two climax, which probably means the story is massively bogged down in the middle with nothing happening, you have nothing to put in the appropriate box. The function of the three-act structure is to remind you to (a) put in regular big dramatic climaxes, (b) keep upping the levels of drama and tension, and (c) keep lowering the apparent chance of the protagonist ever succeeding in their goal. This applies to protagonists who want to win the girl of their dreams (for example) as much as it does to protagonists who want to save the world using the MacGuffin, or whatever. The further the story progresses, the more hopeless it should seem.
Columns four through whatever are for subplots. This shows you whether your subplots are following the approximate shape of the dramatic structure. Subplots should rise and fall in tension roughly as the main plot does: as everything is going wrong in the main plot, so the subplots are going wrong too, amplifying the feeling of desperation.
That's basic spreadsheet plotting. You can see at a glance what main plot and subplots are present, how they each develop, whether there are dramatic crises in all the right place, etc.
The fun part of this spreadsheet is using it to fix your problems. Let's say you have major backstory issues. You think your backstory might be all bunched up in big exposition-heavy chapters. You can create an extra column for backstory, and go down the chapter list recording what backstory you mentioned in each chapter. If you have a bunch of blank boxes (no backstory in these chapters) followed by a huge one (tons of backstory in one chapter) you can see at a glance that the backstory needs to be spread out more evenly.
Or let's say you want to ensure that you're putting in all the necessary scenery description. You create a column for locations, and note down what location each scene or chapter takes place in, and how you described it. If you didn't describe a location, you have nothing to put in the box. The blank box reminds you that you missed out some scenery description. When you flesh out the scene with scenery description, you put that in the box.
Please use your new powers for good, not evil.
