I know that a lot of people like to say "formula." I think that as soon as you start to have a formula imputed to your work, you're in danger of becoming formulaic. So the one formula I have as a rule is falling in love with the material.
It is always character first and story second.
When people say formula, there's almost a little bit of a negative construct to it. It's nice when people describe someone as a "hit factory," but it makes it sound like you're just making baked beans or something.
Really, the idea of creating consistent quality of a show is complicated. It's not like making refrigerators. There's something very specific to each one of the shows, each episode of each show and that involves a really great team doing great work.