This was great! You’re right, there are sooooo many ways to be persuasive. One thing that I do (when it fits) is to take a subject or idea that I’m attempting to share and dramatize it. Exaggerate it. It helps to get a point across. For example, a friend of mine just wrote a great radio ad for a business that wanted to let everyone know of ALL their many services. Which is no easy feat if you’re trying to stay away from being boring. So, he wrote an ad for the business as if you were ordering their services at a drive-thru fast food joint. This particular concept also would fit into your “Comparison” tip.
A narrative technique , also known, more narrowly for literary fictional narratives, as a literary technique , literary device , or fictional device , is any of several specific methods the creator of a narrative uses to convey what they want  —in other words, a strategy used in the making of a narrative to relay information to the audience and, particularly, to "develop" the narrative, usually in order to make it more complete, complicated, or interesting. Literary techniques are distinguished from literary elements , which exist inherently in works of writing.
Backstory is used when the author feels it is important for the reader to know something that has happened prior to the actual events described in the narrative. For example, in the story of Cinderella , we learn that Cinderella's father has lost his wife and married another woman who has two other daughters. This is important for us to understand why Cinderella is treated so differently from the other daughters. We don't actually experience this event in the story. Instead, the narrator gives us this 'backstory' just before the actual first event that we do experience.