"Can I be blunt on this subject? If you don’t have time to read, you don’t have the time (or the tools) to write. Simple as that. Reading is the creative center of a writer’s life."
- Stephen King
I never fail to be amazed at the number of writers who I meet who tell me they don't read. Or they take their inspiration from movies and TV, which would be fine if they were writing screenplays and scripts, but they're writing novels. Different mediums with different requirements. I don't see how you can learn and understand the novel form if you don't read novels.
A lot of writers quote a lot of "writing rules". They tell me "show, don't tell." They tell me don't use adjectives, adverbs, or dialogue tags. And on, and on, and on. But if they were to read as much as I do, they'd see that none of those, or the myriad of other so-called "rules of writing" aren't as simple as "do this" and "don't do that".
Pro writers appear to break those rules all the time. Why? Well, because the rules were generated to help writers in specific situations, but eventually they became broadly applied to every situation because applying a rule is easy. You can fool yourself that you're a good writer because you know how to follow the "rules". But unless you've thought about why you're following the rules and whether you should break them this time, you're not writing at your top level of quality.
What should you do instead? Read, read, read. Look at what the writers of the good books do. Do what they do. Think about your writing as you write and compare the way you're using techniques to the way the pros use them. Then go back and make your writing quality as good as the best books you read. If you can't do that, you're writing's not ready for publication.