One core message
You cannot be calm while delivering something you cannot define, and an audience cannot remember what you never made explicit.
Before anything else, reduce your talk to one sentence containing a verb: the thing you want the room to believe, decide, or do. Every block, story, and slide then earns its place by supporting that sentence, and anything that doesn't gets cut.
This is also your safety net. If you are interrupted, blank out, or lose ten minutes of your slot, you can still deliver the sentence and one reason for it, and the talk has done its job.
It's a coat hook. One strong hook holds the whole coat; a wall of tiny pins holds nothing and just makes the wall look busy.
Instead of a talk titled "Q3 Marketing Update," the speaker opens and closes with, "We should stop spending on trade shows and put that budget into the referral program." Everyone in the room can repeat that in the hallway afterward.