The three rules of the Librarians of Time and Space are: 1) Silence; 2) Books must be returned by no later than the date shown; and 3) Do not interfere with the nature of causality.

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.

History tends to change people who think they're changing it.

She walked quickly through the darkness with the frank stride of someone who was at least certain that the forest, on this damp and windy night, contained strange and terrible things and she was it.

...and the funny thing was that people who weren't entirely certain they were right always argued much louder than other people, as if the main person they were trying to convince were themselves.

That was always the dream, wasn't it? 'I wish I'd known then what I know now'? But when you got older you found out that you NOW wasn't YOU then. You then was a twerp. You then was what you had to be to start out on the rocky road of becoming you now, and one of the rocky patches on that road was being a twerp.

"I'm sorry, I just got carried away," hissed Aziraphale.