If you get the characters right you've done sometimes nearly half the work. I sometimes find I get the characters right then the characters will often help me write the book - not what they look like that's not very important - what people look like is not about their character. You have to describe the shape they leave in the world, how they react to things, what effect they have on people and you do that by telling their story.
My character - and for that matter my worst habits - could only be described by someone else. You can't open a box with the crowbar inside it.
There's that lovely thing for the first month or two of writing a new book: OK, I don't know what that character's going to do, but we'll find out later. After about three or four months you come to that bit where you've got to put some plot in before it's too late, and you have to go back and start inserting plot, and, ooh, I've left out the literature, OK, lets put some in.
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.
In the first book of my Discworld series, published more than 26 years ago, I introduced Death as a character; there was nothing particularly new about this - death has featured in art and literature since medieval times, and for centuries we have had a fascination with the Grim Reaper.
For an author, the nice characters aren't much fun. What you want are the screwed up characters. You know, the characters that are constantly wondering if what they are doing is the right thing, characters that are not only screwed up but are self-tapping screws. They're doing it for themselves.
Plot exposition that can be gently wound out by the authorial voice and internal monologue of a character in the length of a page has to be delivered in a matter of seconds on the stage.
The characters are the plot. What they do and say and the things that happen to them are, in a sense, what the plot is. You can't take character and plot apart from each other, really.
The author can always delve into his own personality and find aspects of himself with which he can dress his characters.
Once you have your character sitting right there in your head, all you really need to do is wind them up, put them down, and simply write down what they do, say, or think.
