I was in Toastmasters for 13 years and learned an easy-to-remember framework of three rules for creating a prepared or off-the-cuff talk. Here it is:
RULE #1 – TELL THEM WHAT YOU’RE GOING TO TELL THEM.
That’s what I just did in the first sentence above. I told you what I’m going to tell you. It alerts the listener/reader to what is coming and sets the stage for the rest of the talk or presentation.