Fantasy author Brandon Sanderson (Mistborn, Wheel of Time, Stormlight Archive) teaches a writing class where one of his lectures focuses on the notion that writ

Fantasy author Brandon Sanderson (Mistborn, Wheel of Time, Stormlight Archive) teaches a writing class where one of his lectures focuses on the notion that writing is more about skill/craftsmanship rather than ideas/inspiration: I want to disabuse you of a few notions. Writing is not about inspiration. Writing is not about ideas. Writing, or more specifically, getting published, is not about luck. What is writing about, then? Writing is about skill. And today I want to try and prove this to you. When someone sits down to play piano for you, how quickly can you tell if they're a good pianist or not? Basically everybody in this room can judge a pianist's level of skill within a minute or two of play. Not exactly, but you can know if this is someone who's good at piano, or if this is someone who's still an amateur at the piano. You can probably tell if this is a master versus someone who's just pretty good. Editors, published writers, people who know what they're doing, can do the same thing with one page of your writing in the exact same way. That is why it's not about inspiration, ideas or luck, because in one page I can judge how good a writer you are. People wonder why can editors reject manuscripts or, in this new age, where we're sometimes bypassing editors, how come the readers just put something down after one page when they haven't given it a real shot. You guys can judge this too. You've read enough, you know enough, you can judge if something is going to work for you pretty quickly. Perhaps not as quickly as most editors can, but you'll know. You'll read a chapter and you'll know if that person is a master, if they're in that medium grade where they've got some good things going on (it's still readable, but they're obviously not a master), or if this is someone's first novel they wrote when they were 12. You can tell all these things. So how do you develop this skill? Practice. He goes on to note that ideas/inspiration are important, but not the most central part of what makes writing effective. Many "creative" disciplines like writing, sculpting, and film are more about practiced and skilled craftsmanship than inspiration and ideas, whereas in some other fields, like maths and scientific discovery, breakthroughs really are about inspiration and ideas.