"If I had more time, I'd have written a shorter letter"
I couldn't find a consensus about to whom this quote is attributed, but the point stands.
Much of technical writing is being precise. A way of sounding more precise and authoritative is by using fewer words.
After the first draft -- but not before that! --, the practice I find the most helpful is simply asking if every word in a sentence is needed. It is often the case the same message can be conveyed more simply.
One might call certain aspects of a written piece to be load bearing. This is analogous to how some elements of construction can be either for visual appeal or for structural soundness.
In most well-edited and acclaimed technical pieces, just about every word is load bearing. This happens not because the author only writes gems, but instead, because they -- alongside their editors -- took the time and effort to remove every non-essential detail.
So, start broadly, gather all that might be relevant, then invest the effort to polish it down to what's truly essential.
The exact same can often be said more briefly, which makes it clearer and more impactful.