My favorite ideas start with a vague irritation - like an itch - and they just get stuck in my brain. They grow and fester until I'm waking up in the middle of the night just to get it down on paper so it will stop haunting me. These unrelenting thoughts nag at me and follow me around like some kind of twisted shadow, growing until I can't ignore them anymore. Then comes the series of "What If" questions inspired by the original thought.
First thought: I hate my GPS system.
What if it got angry in turn and led me somewhere?
Where would it lead me that could be terrible?
What would I encounter there?
Would the GPS settle for driving me off the road, or is it taken over by something supernatural?
Would I die or would I win?
A strange and mystical beast. Or Annie about to catch a ball. She's pretty fabulous. I'm pretty certain she's part goat, bat, unicorn, and Jack Russell.
Strange thoughts pop into my head, but the real trick is getting it to sing on paper. I know an idea has really taken root and turned into something successful when someone I know reads it and looks at me like they are seeing me for the first time. That look usually says, "Who are you and what made you this way?" When writing horror, the words, "But, you look so normal," are actually a good thing.
Where do you get your inspiration?