A lot of people have asked me how I find the ideas for my novels and the process that gets me to a full length book. It has to be different for every writer, but in my case, I take several factors into account.
First, know what you like and what excites you, because if you lose interest half way through, you're done. I like to think of an overall concept or the big picture and if I think it is interesting, then I break it down into an idea - a specific idea. Then, I need a beginning, middle and climax.
If I can get that far, then a main character has to be developed. Who is this going to happen to. He or she has to be likable and has to have flaws. They need a personal life and they need conflict. If a reader doesn't care about your character then they don't care what happens to them. I make a list, create some names and make some general points of personality and looks.
Create the outline. Like I said, you need the start, middle and end. From there, I interject moments, situations and plot specific points that need to happen to reach the conclusion. This is the hard part because you don't want any boring, non-related paragraphs that the reader will want to skim over. It might be fine to do for a fully developed story at first, but I tend to weed them out in the final editing.
Plus, the outline is usually trash half way into the book. Things change. My characters start making decisions for themselves and I can't help it. Once your characters are developed, they will write themselves and then your story will start taking a tangent, but its very important that if you slice, you curve back to the main thread of your story.
If you find you have a rough draft of your novel at the ready. Try this, go into the first few chapters and find a spot where you can start the novel and cut out the original beginning. Most times, my introductory beginnings can be assimilated into the following chapters and if I find a place where intrigue or action starts, then that's where you want to be in chapter one, line one.
Finally, edit - edit - edit. Every few months, go back and read it as if you had bought the book and edit. And finally, this was very unexpected; with every one of my novels, I've found that X-factor idea, that glue or uniting concept that had been missing long after I thought the book was finished. It's like a light goes on and then after incorporating that, I feel I've finally finished.