An excellent introduction to creating powerful messages or 'framing' is provided by the Massive Open Online Course (MOOC) entitled Framing: Creating powerful political message by Delft University of Technology. These notes are taken - sometimes verbatim - from the transcripts and videos.
In this classic introduction to framing, Lakoff argues that: "Frames are mental structures that shape the way we see the world. As a result they shape the goals we seek, the plans we make, the way we act, and what counts as a good or bad outcome of our actions.
Metaphors help people "understand the unfamiliar" and "make someone realise they've only been looking at one side of a thing." Metaphors assist in closing "the gap in people's ability to grasp something, or speed up what they're already on track to see."