Deliver the news as soon as possible, to preempt the rumor mill.
Speak with energy and physical skills to support your message.
Help your audience see the light at the end of the tunnel.
Hedge! Instead, be direct and to the point.
Leave out the rationale. They might see the news through the wrong filter, which puts both the news and you in a negative light.
Be afraid to say, "I don't know." Nothing erodes credibility faster than being caught in an untruth.
Talk too long. Ten minutes maximum. Your audience will be feeling the force of the blow. Respect that.