Writing, for me, is a little like wood carving. You find the lump of tree (the big central theme that gets you started), and you start cutting the shape that you think you want it to be. But you find, if you do it right, that the wood has a grain of its own (characters develop and present new insights, concentrated thinking about the story opens new avenues). If you're sensible, you work with the grain and, if you come across a knot hole, you incorporate that into the design. This is not the same as 'making it up as you go along'; it's a very careful process of control.
Terry PratchettIt takes forty men with their feet on the ground to keep one man with his head in the air.
Terry PratchettAnd Sam Vimes thought: Why is Young Sam's nursery full of farmyard animals anyway? Why are his books full of moo-cows and baa-lambs? He is growing up in the city. He will only see them on a plate! They go sizzle!
Terry PratchettIn all seriousness, people think that it's the ideas that are important. Well, everyone has ideas, all the time. I tend to write mine down and remember them, but at some point you have to apply the bum to the seat and knock out about sixty five thousand words - that's how long a novel is.
Terry Pratchett