You know how when space shuttles are trying to land and the weather conditions are poor, they can't just wait for the weather to clear and land whenever they feel like it? They have to find a window, an appropriate point of atmospheric entry that will get them to their landing site.
Sometimes, that's what it feels like starting a story. I'm in orbit. I want to be on the landing strip. I know I'll get down there somehow, but I have to find the right point of entry. The book will crash and burn if I don't open it in the right scene. There are always a couple different scenes - landing in Florida or California? - but using a different window means the entire flight path will be different. How do I find the one I'm looking for? The one that will lead me to the best darn book I can make it?
That's where I am right now. I'm orbiting my next book, trying to figure out the right moment to fire the afterburners. Wish me luck.