It's very much like refactoring code. You can do it on a higher level by cutting out entire chunks of code that don't really need to be done, or on a low level by being familiar with the language's helpful syntactic sugars, best practices, to make the meaning clear and less obscured by boilerplate and "syntactic chores".
I noticed the effectiveness of low-level refactoring in prose when I first started writing academic papers. Since page limits are strict, you need to pay attention to eliminate any words that aren't necessary and are thin on semantics. This doesn't mean writing in staccato. But when you spot a paragraph where a single word spills over to an extra line, it requires a specific learnable skill to rewrite a sentence or two to eliminate the extra line. You can often tell how much someone wordsmithed around on a paper by seeing how long the last line of each paragraph is.
Of course sometimes gains are on the high level, I'm not saying that good writing is just about messing with the low level of the actual words and the grammar. Similarly to the debate whether premature optimization is the root of all evil, it's about a balance in writing too. First you must have clear thoughts on what to say and what you can leave out. But at the end, when things have settled, it is worth to go over it once again at specific places and low-level edit things to be snappier, counting words, letters and millimeters on the paper.
> I didn’t have time to write you a short letter, so I wrote you a long one.
From: https://www.futilitycloset.com/2009/10/21/pen-mystique/
My dear Morse:
It was very pleasant to receive a letter from you the other day. Perhaps I should have found it pleasanter if I had been able to decipher it. I don’t think I mastered anything beyond the date, which I knew, and the signature, at which I guessed.
There is a singular and perpetual charm in a letter of yours — it never grows old, and it never loses its novelty. One can say every morning, as one looks at it, ‘Here’s a letter of Morse’s I haven’t read yet. I think I shall take another shy at it to-day, and maybe I shall be able in the course of a few years to make out what he means by those t’s that look like w’s and those i’s that haven’t any eyebrows.’
Other letters are read and thrown away and forgotten, but yours are kept forever–unread. One of them will last a reasonable man a lifetime.
Admiringly yours,
T.B. Aldrich
In nearly every example of this, I got (marginally) better grades than them.
> Keep sentences brief; unnecessary filler obscures your point and bores the reader.
"Brevity is the soul of wit."