The four considerations above help me work with the sponsor, change champion, and the person in #3 to chat the message and determine the vehicle.
Types of vehicles include • website posts • message or collaboration boards (like Slack and SharePoint), • video messages • small group meetings, large group meetings • training materials, games/trivia experiences • electronic notice boards in offices • computer desktop or application messages • good ole email • and, if the culture allows, even physical bulletin boards and desk drops.
No matter which path we take (of course, multiple ways are best!), it's best practice to reiterate why the change/event is happening from the company and employee viewpoint. Include a way for the receiver to take action, and give an interaction. Of course, a way to get more information is always good too.