There are two schools of writers (probably more): those who stick to “the rules” and those who don’t believe the rules exist. I tend to fall in with the latter. While there are guidelines that most writers should and do follow, I wouldn’t count out someone who breaks every last one of them with absolute brilliance.
Elmore Leonard recently wrote an article intended to help writers stay invisible. Most authors probably think they do a pretty good job of this already (including myself), and that’s precisely why it’s a good idea to have another writer you trust read over your stuff. Read Elmore Leonard’s Ten Rules of Writing right here.