I've spoken to aspiring writers who are wavering on what to write about. Well, pick a topic that will garner interest. Then, the trick will be finding your writing voice. It's easier said than done. You have to work at it on a consistent basis. But don't worry. Practice makes perfect. I'm on my third book (I've lost count of articles) and I am just now finding my voice. Now, everything I write, no matter the subject or genre, should sound specific to me. That's one key to building a following.
I'm currently reading "Gone For Soldiers" by Jeff Shaara. It is about the Mexican War, but it reads just like his Civil War books. His father, Michael, sounded the same when he went from a Civil War novel to a baseball novel. Reading works by authors in the genre in which you are writing is a great way to learn the craft. Read as much as you can, learning how they craft sentences and paragraphs. Don't copy, of course, but pick up pointers from those writers who are successful. Before long, you'll be on the road to success. Of course, there are books, blogs, manuals and conferences that will also be beneficial on the art of crafting, but reading what is selling is the best teacher for me.
The next logical step is then writing something that will sell well. Remember, pen something the media will salivate to cover. Once it's on their radar, word will spread.