I was asked recently where I get the inspiration for my books. As I thought about it, I realized inspiration is needed in a variety of ways.
Inspiration is needed for the plot itself. In my case, it's planning the crime. I usually get inspiration for my plots from real life cases, declassified government documents and newspapers or documentaries. Then I make my own twists on them, such as using Enron's method of raising electric prices on another commodity - such as oil.
Inspiration for characters. I am an avid people-watcher. I look for odd characteristics; a particular limp, a way of raising an eyebrow, the use of hands while talking, a nervous chatter... There are people everyone meets with whom they take an instant dislike. I wonder why, and look for those characteristics that repel people. And with those that everyone likes, I look for what draws people to them.
Inspiration for scenes. I love the use of weather to ratchet up suspense. I look for the types of weather that frightens people - thunderstorms, of course, snowstorms, hurricanes, tornadoes... The types of weather that can suddenly knock out electricity and leave you in the dark, where everything appears differently. I look for places where the scenes should take place; having two talking heads throughout a book makes for a very boring one, at best. What locales would further my plot, enrich it, provide it with a distinct flavor?
Inspiration for props. We don't hear much about props in a book, but I am a very visual person. Ever watch an episode of Two and a Half Men? They sometimes meet in the kitchen while getting something out of the refrigerator, a cup of coffee, while having breakfast... Berta often is seen carrying a load of laundry through the house. These are all props. They are used in every scene to further enrich it and provide layers that make it real and interesting. In a book, it breaks up the monotony of a conversation and allows the opportunity to show more of each character and scene.