So here's something I never consciously think of but probably should when writing - framing. What do I mean by that? Well, it's how you tell the story.
Oh, wow, that clears it up. Good job, me.
Okay, okay. Let's use an example. Let's say my main character is a murderer. I could frame the story in a way that shows the reader my character is an awful terrible despicable human being and by the end of the book she gets what's coming to her. OR I could frame it in a way that humanises her and shows that she had to kill someone to save her best friend from a fate worse than death. The way you frame a character like that can completely change the kind of story you tell.
Whether you're ever consciously weighing up the options or not, a book is framed from its initial concept. There's an idea buzzing around my head right now that, framed one way, would make it YA, or, framed another, would tip it into adult thriller territory. Not even sure if I'll ever write it, but it's fun to pull it apart and have alternate versions floating around.
I've only really recently stopped to think about framing. I suppose it's so innate to the story when you first come up with the idea it's not something you sit back and think about. But if your story or your character aren't totally nailed down, it can be fun to consider it. You never know where framing will take your story...