How do you pick just ONE idea? Great question.
keyboardsmashwriters on Tumblr have great advice on this:
–All ideas sound like good ideas, but there’s no way to work all of them in, and different ideas will affect the plot differently.
The potential in each idea, while seemingly the best thing ever in the beginning, might lose their luster once worked into the plot. Here are some things I consider when at this point:
How will the characters be affected by this? What might the characters do with it? Will this add new conflict? Will it impact their individual character arcs or how they move on in your story?
Will outlining help? Sometimes characters come to crossroads in my story and I play out two different scenarios to find out where it leads, and whether it takes us off course or keeps us moving forward. If outlining different ideas helps you see clearer into the future, this is a good tool to use. Outlines are like big dry erase boards, after all.
Write little snippets or passages. See what sort of feel it generates and if it’s what your story needs. You might see if something doesn’t make sense or is too overbearing, or if ideas are clashing or not even doing enough to make a difference in the story. It might be that some things you want to do simply distract from the others.
Combine ideas. Sometimes both ideas work for your story, and sometimes both ideas work even better if you combine them.
The first draft is always allowed to change. Maybe you write the first few chapters and decide something’s not working. That’s okay. Take a break from it, set it aside for a while, and do some thinking. Figure out if anything needs added, or if anything needs the guillotine. Ask a writerly friend or two to read and see what they think so far.https://keyboardsmashwriters.tumblr.com/post/44818116772/choosing-ideas-and-endings
I totally fell victim to this one. My first draft of Violet was a mess — my main character was stuffed full of psychic abilities (she could see visions of the future, move things with her mind, speak to ghosts… it was a lot to keep track of), secret family members (EVERY character had one), and a masked villain (think the Masked Figure from Scooby-Doo 2: Monsters Unleashed).
Understandably, I had to take a step back and think about what didn’t work.
In my experience, it was all about trial and error.
There was a lot that didn’t work together, but there were some really good parts that did work together. Without that exploration I wouldn’t be at this stage with Violet.
Remember, your first draft is allowed to be bad. Give yourself the permission to write too many ideas into your novel. There are no rules in Draft One. It’s No Man’s Land.