There are some courses on Poynter. One the best material I've seen was '50 writing 'tools' it was a serie of blog posts that are no longer online but you'll have no troubles finding it on the web.
> Roy Peter Clark... whittled down almost thirty years of experience in journalism, writing, and teaching into a series of fifty short essays on different aspects of writing
https://www.poynter.org/reporting-editing/2006/fifty-writing...
And it links to a book on the topic too.
> Roy Peter Clark... whittled down almost thirty years of experience in journalism, writing, and teaching into a series of fifty short essays on different aspects of writing