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.
Terry PratchettThe people of Ankh-Morpork had a straightforward, no-nonsense approach to entertainment, and while they were looking forward to seeing a dragon slain, they'd be happy to settle instead for seeing someone being baked alive in his own armour. You didn't get the chance every day to see someone baked alive in their own armour. It would be something for the children to remember.
Terry PratchettYes, sir, thank you, sir, and I wouldnโt trust me one little inch, sir. I knows a bad one when I sees them. I have a mirror.
Terry PratchettI'm a fantasy writer, called a fantasy writer. But there's very little, apart from one or two basic concepts in 'I Shall Wear Midnight,' which are in fact fantasy. You have sticks that fly, but they're practical broomsticks, with a bloody great strap that you can hold on to so you don't fall off. And you try not to use them too often.
Terry Pratchett