Tiffany got up early and lit the fires. When her mother came down, she was scrubbing the kitchen floor, very hard.

"Er, aren't you supposed to do that sort of thing by magic, dear?" said her mother, who'd never really got the hang of what witchcraft was all about.

"No, Mum, I'm supposed not to," said Tiffany, still scrubbing.

"But can't you just wave your hand and make all the dirt fly away, then?...I thought you just had to wave your hands about."

"That works," said Tiffany, "but only if you wave them about on the floor with a scrubbing brush."

--Terry Pratchett, Wintersmith