On several occasions I hired a communications consultant for annual key management team meetings to impress on our management group the critical importance of the skill — communications.
Often the message was a rehashing of the basics as if those are not present then messages (written, spoken) fail to achieve the goal. Consider the graphics below on Role, Process, and Buy-in. Of course the degree of planning would vary depending on complexity of project.
In the end our consultant would make sure the group left with the same thought as a takeaway and consider in their work…”when something goes wrong, 90 percent of the time it can be linked to poor communications”.