These days, you don't just break into comics once. You have to break in again and again after each job is finished.
Over the last ten years, breaking into comics has changed so much. There used to be specific ways about how to do it ... and now, just like there are so many different ways people are getting exposed to comics, there's no single way that people are breaking in anymore.
To the folks asking how they can become a comics writer if Marvel doesn't accept submissions... YOU WRITE COMICS!!