Elana Johnson and friends started an amazing online writer's retreat. For FREE! It's over now but you can still go read all the educational posts from professionals in the writing business.
One of my very favorite post was from editor Molly O'Neill titled "The Essential Invisible Thing".
She talks about her definiation of craft: the work of writing.
"Because strong craft? It speaks for itself. It wows its readers. It
elevates a story to something even greater than itself. Craft is like
meditation, or prayer, or exercising. It’s mostly silent, and somewhat
hidden, and deeply personal. Few people will notice that you’re working
on it unless you tell them. But your self will be enriched by it, and
your work will be strengthened by it. It’s a set of expectations that
you can set for yourself, and if others (agents or publishers or
booksellers or educators or critics or readers) eventually notice it,
too, well, that’s well-earned gravy. Attention to craft is like the best
possible kind of creative gift that you can give to yourself . . . that
just might also help develop your career, too."