Ask HN: What can I include in an effective communication workshop?

I am putting together a half-day or full-day workshop for effective communication - written, powerpoints, narrative writing etc. It's a tech/research audience and now working remotely.

No fluff and only actionable advice the attendees can use on a daily basis.

Do you have any suggestion on things that I could include? Including great material already written that I could repurpose?

So far, the Army Writing Manual is one of the better resources I have come across.