Brick or Stone?
While a certain amount of writing out your thoughts without any concern for structure (sometimes called free-writing) is a perfectly acceptable practice, you’ll never get to a publishable piece if you don’t do some organization, if at least after the fact.
Some people seem to think that writing, especially fiction or nonfiction, has to be so much “discovery” that any kind of planning and organization is anathema to them. Behind this attitude appears to be a fear of the writing becoming too formulaic, as if structure rather than lack of originality is the culprit. In their mind, a well-structured piece of writing would be compared to a brick wall, where every element in the wall is virtually identical — it fits together well, but it is dull and repetitive.
Not so, however. A well-structured piece of writing is more like a stone wall, with each piece of stone a unique size and shape, and with all the pieces fitting together at various angles and positions. A good stonemason needs to choose carefully where each piece of stone fits, like assembling a jigsaw puzzle.
Only after the wall is complete does the stonemason step back and say, “It’s perfect — every stone in the right place.”