Usually the characters are the first thing that comes to mind for me. Occasionally there's a crime that I want to use, but it doesn't matter. The important thing is to find powerful goals and motivation—the kind that creates conflict and compels the reader to turn the pages.
When I have a serious idea, I try to come up with the goal, motivation, and conflict for two or three main characters, the heroine/hero or both, and (since I write suspense) the villain. Everyone needs a reason for their behavior, and the stronger the reason, the more compelling the story will be.
Weak motivation makes a weak story. Say the heroine, Millicent, is usually a nice honest person, someone we could like and want to know, but today she steals a rare plant to make tea from. Why? The reader won't be happy about finding she's a thief. Did she just crave the tea and thought one little plant from the scientist's greenhouse wouldn't hurt? Poor motive. But what if her child is terribly ill and the only thing she can keep down is tea from this plant (not exactly believable, but this is to illustrate a point, not become a great plot). Millicent is penniless, has lost her job, her house is in foreclosure, and her child may not last the night. So her reason for stealing becomes more acceptable. She has a strong motivation. What if some enzyme in the plant is a possible cure for the illness? She wants to cure her child, so she has a strong goal, one we can share in.
You can always ask Why? and What if? Increase the stakes for the protagonist until you have something the reader will really care about and sympathize with. A deadline can add to the suspense and motive. If Millicent's child is near death, she can't wait around till she earns the money or can convince the scientist to help her. What if he's already turned her down? She's tried the legal paths but at this point, has no choice.
Now for the bad guy. What if he's the inventor of a new drug that contains the enzyme and stands to make a lot of money from it? He needs a motive too. Just wanting the money is poor and not something we'll have any sympathy for. He needs a compelling motive too. Let's say he grew up poor and his mother died because the family couldn't afford medical care. That's why he became a drug researcher. He wants to create miracle cures and make money, but because power corrupts, he's become selfish and greedy. He can have all kinds of secondary reasons and complications. But the villain needs a goal and a motive too. The story will be a much more compelling read if their goals and motives are strong and in direct conflict.
Keep adding to the Why? If your heroine is a doctor, make her the only doctor in a small community during an avian flu epidemic. She's exhausted but still going. So have her run out of medicine. Block the only road in or out—how about a landslide caused by the forest fire that drove the chickens carrying the flu into town in the first place? The events that worsen the situation should be tied together and related, not acts of fate that come out of the blue. Ask what other terrible things could happen to worsen the situation. But don't forget the bright spot, something to give a faint ray of hope. Maybe the child who drank the tea survives (combining stories, I know), but the fire destroyed the plants. And so on. As you write, details will come, things will change, and surprises will emerge. But at least you'll have the basis for a good story.
Ellis Vidler is an editor and the author of Haunting Refrain, a romantic mystery with a touch of paranormal. It's available on Kindle. She co-wrote The Peeper, a suspense novel, with retired LEO
Her new book, Cold Comfort, romantic suspense, will be available from Echelon Press this month. When Christmas shop owner Claire Spencer is attacked, she hires PI Ben Riley to find out why. Together they find everything she believed is a lie, but the truth is . . . Cold Comfort.
You can find her at www.ellisvidler.com or her blog, http://theunpredictablemuse.blogspot.com
Links: Haunting Refrain http://www.amazon.com/Haunting-Refrain-ebook/dp/B00336F3QE
The Peeper http://www.amazon.com/The-Peeper-ebook/dp/tags-on-product/B003VYBQGY
Cold Comfort http://www.echelonpress.com/