Pinterest is a massive boon to my health-related blog (See those pinboards). However, I pin a lot on that one. I had a board for my writing but nothing major. But I think this should be part of an author platform. So I made a separate account just for writing.
You want a business account for sure and all content to revolve around the topic at hand. Make sure every board has a description.
And you have to make pinable posts. With images that work for Pinterest. I use the same template for my writing one as then they all match. But for my health one, I have 5 or so templates I use depending on the post.
I use Tailwind for my pinning. It makes it easier to pin at peak times and schedule a lot of pins. Check out Typical results for Tailwind users. It has been great for my health-related blog but I don’t yet need it for this one.