Frankly, there are only three “rules” to being a successful writer:
1. Read. Read everything. This is how you learn both what you like, and what you don’t like (and you sure shouldn’t waste time writing stuff you don’t like, no matter how popular you think it might be)–and how you begin to learn what writing techniques are, and how they work.
2. Write. You can read all the books about writing and take all the classes about writing that you want (and I’m not saying these are pointless; they’re great for some people, not so much for others)–but the Horrible Truth is that nothing will teach you to write, except the act of putting words on paper. I naturally can’t guarantee that you’ll be published, successful, or rich–but I do guarantee that the more you do it, the better you’ll get at it.
and the third rule is the most important:
3. Don’t Stop!!