"No" Is A Complete Sentence
How often do you answer "no" and then feel compelled to say more, to explain yourself?
"No" is a complete sentence. No explanation or justification is needed.
Women seem to be more impacted than men on this one. We tend to say more than "no" to get people to understand our position. Like if we don't offer explanation we'll be thought less of.
But "No" means "No". Say it. Mean it. Move on.
If somebody needs more than that, bite your tongue.
There's so much more you can do to strengthen your communication.