Here's how you know you're watching a movie that was adapted from a Stephen King book: a) something weird is going on; b) the people in the story don't know that weirdness is going on; and c) --and this is most important-- one of the characters, probably the main one, is a writer. Stephen King writes about writers all the time, because that's what he knows. But here's what I learned in my time of writing about writers: mostly, it's only writers who are interested. Writing about writing is all well and good, but it's even better if you don't do that at all. I'll tell you why.
People are always interested when they find out that I'm a writer...at first. Once they understand that writing is me sitting on my couch and staring at my screen, they realize that writing is actually pretty boring. It is tedious, hard work. And it isn't interesting. This is why you shouldn't write about writing.
When you're a writer and that's what you know, it's natural to make your characters writers as well. But maybe you could change that, slightly, to make it more interesting. Maybe the character could be in advertising instead. Maybe he writes travel brochures. Maybe she writes book reviews, or restaurant reviews. This allows you to take your character out from behind the computer screen.
Books are supposed to mimic life, after a fashion. They should be relatable and believable. But the day-to-day details of life are boring. You can still write a believable book, and create a character that you can feel strongly about, without all the boring parts. So the next time you want to put your character in front of a computer screen, think about a different way you can send them to work instead. Writing about writing will make a character come to life for you, the writer.
Now, how are you going to make that person come alive for the reader?