Major focus on message
Make one main, clear point per piece, that's it
Particularly in non-fiction/persuasive/social action-related writing, before you set out to write, decide on the one crystal-clear message for the piece, write, then edit with that message in mind, asking yourself, “does this sentence/phrase/paragraph help me make that single crystal-clear point? Or, does it distract and feel tangential?”
Because here’s where this gets off track for even the most expertise-y experts trying to share their knowledge: when there isn’t a lot of self-trust going on, we tend to think about it in terms of “oh, I have to put all of these important points into this one piece and show absolutely everything I know.” But, it’s essential that you believe there will be other pieces, and in those pieces you’ll make other points and each point will have its due. It’s essential to believe that not only for your own well-being, but it’s essential to operate from that place because to do otherwise will make your writing feel crowded and overwhelming to the reader. Your work can be a chain, with each new work springing from the one before.