In a story--and any time you communicate an event, that is a story--one has to separate breaks. First, the simplest way I do:
1) Meta breaks: In a written format, this would be paragraphs, chapters, line breaks, or whatever else; when speaking, it is a pause or change in tone; in acting, a scene break, act change, or any in the previous; in movies a fade to black or any in the two previous categories. This list is not exclusive.
2) In-story breaks: Times when the character took some time. Examples are taking a break from whatever the character is doing, be that in writing, reading, fighting, or anything else. This may overlap with the above.
What is fascinating is exactly how much difference separating these two breaks makes. Say an author goes through a day in the life of one of her* characters. In the first telling, she put down everything that happens, and the character's feelings about all of it.
Wow. That is boring.
Okay, she goes back. Looks it over. And she asks herself that most important question in all of fiction, nay, in all of storytelling:
"What am I trying to write?"
The simple truth is, if the author can't figure out an answer to the question, the editing process is going to go nowhere. In Rapunzel, you will almost never hear what happens to her mother and father after she leaves in anything but the scantest of detail. The same goes for the witch. Why? Because the story is about Rapunzel. Adding all that information just breaks from the main action, the main story. It is not about her parents, or the witch, or even her prince. It is about her. So those are the details that got passed down.
Not knowing where your story is going when you write it? Fine! There's no problem with that. But trying to edit a story when, when it comes right down to it, no one knows who or what it is supposed to be about it going to end in disaster. If someone didn't know the story was about Rapunzel, would that person cut the description of the Prince's childhood, her parents', hers? Has to cut at least one, all these things are cluttering up the book and we don't get 90% of the loose ends tied up! We're breaking from the main action in half the book; I don't even know what the main action is supposed to be.
So, what is the story? Is it about Rapunzel? Her Prince? Their love? The witch? Her parents? A young boy who watches some or all of it happen and his response? Something completely esoteric?
There is no need for that to be the only thing in the story--no matter what the response is, all of those will be affected by the environment. But the majority of the book should be based around the focus of the book. The rest are breaks. A book without breaks makes no sense, a book that is mostly breaks is just plain weird. Though that can be done well, in order to do weird things well one has to be A) really lucky or B) aware of the weirdness.
[announcer voice] Step right up and try your luck!
* I dislike saying him or her.