You know your basic story. You’ve fleshed out your main characters. If you’re anything like me, once you know your characters, they’ll start changing the plot on you. This is a good thing. Character-driven stories are easier to write and more fun to read. Let them take you where they need to.
Read over your original outline. Read over your character sketches. The thing you want to remember is that right now, none of it is in stone. You can still change anything you want to. And again, changing things at this stage is a lot easier than changing things later.
Now that you have the characters and outline in your head, it’s time to write the Big Outline. Unlike the previous one, you want to write down everything you can think of in this one. Include, plot, subplot, character moments, and anything else you think you might need. This outline should be a few pages long. Write it from beginning to end. If your story jumps around in time, this is a good chance to make sure you have the chronology correct.
If you’ve done your job right, there will probably be a few surprises. Now that you know who you’re dealing with, they’re likely to make different choices than you had them make in the original outline. Now is the time to let these things happen. If it goes somewhere that doesn’t fit with the rest of the narrative, you can always junk it or use that particular part for another story. And you can always change the character if you need to.
Once you’re finished writing the outline, read it over a couple of times. This is your story. If you don’t like it at this stage, change it. You’re going to be spending the next few weeks wading through this story so if it isn’t a world you want to be in, fix it fast. If the author isn’t interested, then the readers definitely won’t be.
At this point, there are a lot of people out there who would just start to work on the actual writing, but I don’t think it’s time yet. There are still things you should do before you hit the ground running. We’ll get into those next.