There are many good sources on writing. In my classes I often assign:
Deirdre McCloskey, Economical Writing. University of Chicago Press Press, 3rd edition, 2019.
Available online is a 1986 article from Economic Inquiry that was evidently the starting point of the book, along with a more recent "executive summary" in the Eastern Economic Journal.
I also recommend:
Joseph M. Williams, Style: The Basics of Clarity and Grace. Third Edition, Longman, 2008.
Brad DeLong calls this "the only truly useful book on English prose style that I have ever found."
When he was a Ph.D. student at UConn, Nick Shunda, now at the University of Redlands, worked with the UConn Writing Center and put together a series of workshops on writing in economics. Available here in pdf and PowerPoint.
And don't forget the resources of the UConn Writing Center.