Write. Write. And write more. But always write what you know, at least to start off with. Write what you feel comfortable writing about. Writing in a genre you like reading or watching for that matter also helps.
Find your own style, experiment a bit if you like. You can even right from experience and elaborate certain events that's happened to you to fit your novel.
But most of all, create a following months in advance to when your book is released. In fact, start before you have even written your book. I didn't and it feels like I'm playing catch-up.
Out all of the advice I give you, this one is the most important. Don't give up. If you really want it, you'll eventually get it.