Jim Butcher's writing advice is built on a premise he states plainly: he doesn't consider himself naturally gifted, and everything about his career came from learning and applying craft on purpose.

The Direct Answer
Write every day, even if it's only a sentence.
Butcher says momentum matters more than length on any given day, and credits structure learned in a college writing class over natural talent.

Momentum Over Volume

Asked how new writers should build a habit, Butcher has been direct.

Writing is about momentum, so get that momentum, set your time aside every day and stay honest.

Jim Butcher, Sword and Laser podcast interview

The advice cares less about hitting a word count than about never letting a day pass with zero contact with the manuscript. Even a single sentence keeps the thread alive in a way that a skipped day doesn't, and Butcher has said explicitly that a small amount of progress still counts as progress toward the end of the book.

Craft Over Talent, By His Own Account

Butcher has said his first six to eight attempts at a novel were unreadable, and that everything since came from deliberately applying structure he learned from his writing teacher, Deborah Chester, rather than from any gift he was born with. He's said he doesn't spend much time consciously thinking about theme while drafting either. If the structure and characters are built properly, he's said, the theme tends to surface on its own, sometimes not becoming clear to him until well after a book is published.

For how this philosophy plays out across eighteen Dresden Files novels and the outline he's used since college, see the complete Jim Butcher writing routine.

What You Can Steal