I will not tell you how to come up with story ideas. A lot of books will. I think it’s crap.
Every writer I know has a bottle neck of ideas. Like many others, I keep a little book that I fill with things that spring to mind on a random basis: story ideas, titles, scenes, random dialogue. It’s called inspiration. If you don’t have it, you’re not a writer.
Working backwards. Victim’s Song started by the sheer need to shoot something in one location. I knew I was actually going to direct it. So my question was, “Why would someone only be in one location.” The answer was simple. They can’t leave. “Why can’t they leave?” Someone tied them to a chair. “Why did they do that?” And so on until I found I had a story coming together.
From a title. My most recent screenplay came completely from the title. I had come up with what I thought was a bad-ass title. I wrote it in my little book and forgot about it. Eight months later, while I was on a plane about to land, I suddenly remembered the title. I pondered it’s meaning. What would that movie be about? By the time we touched down I had the entire story structured, characters mapped out, and even bits of dialogue. I had to take a pen to a napkin and jot things down.
Without inspiration there can be no passion. Without passion there can be no art.