For the modern content creator (artist, blogger, vlogger), the modern corollary is to create a lot of content. People have replicated this strategy to great effect on YouTube and Twitter. I’m even doing the same on Medium, producing content with the intent of building an audience to which I can launch books.
This modern corollary isn’t even so modern. Stephen King wrote quite a few novels before one of them was picked up by a publisher. People need a lot of practice before they’re any good.