on Jane Friedman site:

One of the most important abilities a writer can hone doesn’t involve writing—at least not their own.

Learning to objectively assess other people’s stories, and pinpoint what makes them effective or not, will do more for your own writing craft than even psychologist K. Anders Ericsson’s much vaunted (and misinterpreted) 10,000 hours of practice popularized by Malcolm Gladwell.

That’s not to denigrate the importance of actually doing the work of writing. But no amount of putting words on the page will teach you as much as analyzing what makes story work and training your own editor brain.

Analyzing story like an editor informs every element of writing and every skill a writer must develop—not just editing, but also drafting and revision, and storytelling skill as well as craft skills.

The ability to see our own work clearly is one of the greatest challenges of writing. Authors fill in the blanks of their characters and world and stories in their heads without realizing whether it’s coming across effectively on the page to readers. It’s almost impossible to assess our own work as objectively as we can with other people’s.

That’s why practicing the skill with stories we did not create is one of the best ways of learning to see the component parts of effective story and internalizing those skills in the ones you do.

And no matter where you are in your writing career, whether multi-published or at the beginning, you already have the main tool you need to master this skill: yourself.