Brevity has its place, but no greater a place than thoroughness. Thoroughness takes time, but it also pays a greater dividend.
In whatever you're trying to say or trying to do, stop trying and get to the point.
Thoroughness does not require complexity or volume or heft. It does not require that you undertake a lengthy, prolonged, and arduous journey, like this one.
Clarity never increases by adding things.
When in doubt leave it out, and be doubtful frequently.
If you have a lot to say, you're already saying too much. If you have a lot to do, you're already doing too much.
Start with a single idea, one clearly defined action or one point that you want to get across and express that as simply as possible.
If somebody is about to get hit by a car and you want to convey the danger to them, what do you say?
"Excuse me, sir. There's a ten-thousand pound vehicle coming down that street and if you do not stop walking it will surely hit you and cause bodily harm. May I kindly suggest that you do not cross the street until the vehicle has passed?"
Absurdity! They'd be dead and you'd look like a fool for taking so long.
All writing should be as clear as that. All action and communication should strive to express with such clarity the purpose for its existence, or it should not exist at all.
Get to the point.