Here’s the thing about The Big Idea, at least in my opinion.
It’s not such a big deal.
Yes, the Big Idea is great, and you want it to have that compelling “elevator pitch” quality that will reel people in the second they hear about it… but the Big Idea is really a very small part of writing any story, in any medium. The meat is in the details.
I remember realizing this vividly when I was in high school. It was 1988 (go ahead, do the math), and three movies came out at pretty much the exact same time, all with the same Big Idea: spend some time in a body not your own, and gain a new perspective on life.
The movies? Vice Versa (dad and kid exchange bodies), 18 Again (kid and grandfather swap bodies), and Big (kid makes a wish and gets an adult body).
Most likely, you only know one of those movies. I actually saw all three, and you didn’t miss anything.
And yet… they all had the same Big Idea.
The difference, of course, is in the execution. A Big Idea might sell a project, but if the execution isn’t solid; if the details aren’t specific, unique, and compelling, the story will be hollow, and it won’t succeed.
Publishing is a business and it’s certainly easier to sell your book when you have a Big Idea “hook,” but the biggest mistake you can make is thinking you’re done once you have it. Got a hook you love? Great. Set it aside and don’t concentrate on it while you figure out your characters, your world, and all the little idiosyncrasies that make your story ring true. Once that work is in place, you’ll have more than a Big Idea, you’ll have a great story that works.
Have you found this in your own writing? Do you tend to be inspired by a Big Idea, then work back to fill in the world? From what I’ve gathered in his author notes, that was the process of Stephen King’s Under The Dome — he had an immediate Big Idea of a Dome sitting over a town… but the story only works because he moved beyond that idea to get intimately involved with every personal story within that town. Or do you start your stories with a character that speaks to you, then follow him/her until you find the story, and whatever Big Idea naturally evolves?