Do you let the rhythm of your writing dictate a lot of the information you include (i.e. you’re subconsciously aware that the next sentence needs another clause or two to sound good, so you select more details to balance it out) or do you always think up exactly what needs to be conveyed and then put it down as clearly and succinctly as possible?

I used to do the latter, but I had trouble creating longer, more varied sentences. After I thought up ideas, it was difficult to stretch or squash them in a way that sounded good. My writing was choppy for a long time. I eventually started covering what needed to be covered and then expanding the resulting sentences with whatever relevant details I could think up until they were long or short enough to sound “right”.

It’s a useful trick, but it worries me a little because I feel like I don’t have as much control of my writing as I want. When I make up my mind to include a scene, a sizeable chunk of the scene's details/description are pertinent but improvised. It's difficult to plan ahead if the end result of each chapter is usually very different from what you envisioned.

Is this kind of improvisation something any of you do when constructing your sentences? And if not, and you think it's a very bad habit, how can I get around this? I don't know how else to create writing that flows, because simply finding ways to join the sentences I would otherwise write isn't enough to give my writing the rhythm it needs*.

*IT MAY HAVE SOMETHING TO DO WITH THE WAY I THINK; THE IMAGES I COME UP WITH (AND, AS A RESULT, WANT THE READER TO SEE) TEND TO BE VERY SIMPLE. THEY'RE EASY TO GET ACROSS AND SO THEIR DESCRIPTIONS ARE OFTEN SHORT.WHEN I ADD DETAILS TO MAKE A SENTENCE FLOW, THE END RESULT SOUNDS GOOD BUT USUALLY DEVIATES SLIGHTLY FROM MY INITIAL OVERALL INTENTION BECAUSE I ALREADY GOT EVERYTHING I WANTED ACROSS WITH THE FIRST PART OF THE DESCRIPTION.

FOR EXAMPLE, LET'S SAY I WANT THE READER TO KNOW THAT THERE IS A BOY MOVING TOWARD A HOUSE. LET'S ALSO ASSUME THAT (IN CONTEXT) THE SENTENCE ISN'T LONG ENOUGH. I DON'T SEE HOW TO DRAW OUT THE IDEA, AND THE SENTENCES ON EITHER SIDE ARE TOO FAR AWAY (CONCEPTUALLY) TO MELD THEM WITH THE CURRENT SENTENCE. IT WOULD BE JARRING TO THE READER. IN THIS CASE, I MIGHT GIVE THE BOY A LIMP OR STRANGE CLOTHES OR SOME OTHER TRAIT I DIDN'T PLAN FOR TO BULK UP THE SENTENCE, AS THERE ISN'T ANYTHING ELSE RELEVANT I CAN THINK TO ADD TO FLESH IT OUT.