Writing isn't just about telling a story. We have to do so much more than that: brainstorm, outline, prepare, research, write, re-write, edit, proofread. And that doesn't even include the juggling we do, just to tell the story. We have to know about grammar and formatting, about plot and character, about setting and tone. About pacing and dialogue, exposition and flashback, punctuation and description. And then, of course, there's the all-important "showing-not-telling," and making the plot and characters "ring true."
Whew. I'm tired, just thinking about it.
It's such an intricate balance of things, telling a story. If one element is missing, or needs work, it throws the rest of the story out of whack.
I guess I've learned to tell the story the best way I can in the rough draft, not concerning myself too much with anything else. Then, upon many other read-throughs, I can catch those other things. I can look for my known weaknesses and isolate them (dashes!!! passive voice!!! lol). I can focus more specifically on things like pacing, or on detail and cliches and character development.
I really think we writers have to be jacks-of-all-trades. And if I think too hard about it, this whole process can get quite overwhelming. That's why I try to slow down and focus on one thing at a time. Stone by stone. Brick by brick.