When I preach I want to be:
Declarative: Preachers don't share thoughts or give advice. They herald something that's happened. That must be the over-riding influence on a preacher's tone because it's the over-riding burden of the preacher - the telling of news.
Doctrinal: I don't mean preachers should work their way through systematic theologies. I mean that preachers must herald the gospel of Jesus Christ. I'm not interested in a regurgitated commentary or a reading comprehension excercise. Don't preach the passage - preach Christ from the passage.
Devotional: What is meant to come by hearing? Faith. That's the aim of the preacher - loving, dependent trust in Jesus Christ. The preacher, using the Scriptures provided, paints Jesus in such colours that hearers - wracked as they are by sins and suffering - might have confidence in Him, and even love Him.
And if you can do all that without forcing it into 3 alliterative points, so much the better!