Power comes from powerful phrases; it also comes from knowing where to put those phrases. Good speakers use an influential technique used by trial lawyers—people who sway audiences for high stakes. It's called the doctrine of primacy and recency, and it refers to people's tendency to remember beginnings and endings.
Given this tendency in listeners, effective speakers will put their crucial information at the beginning and end of each sentence, and paragraph, for the entire speech. Whatever comes in the middle tends to get lost. Listeners' concentration is high with the first word, wavers as a statement continues, and is high again with the last word or phrase. If you say the sentence "My boss is fair, observant, considerate, and generous," people will remember fair and generous. Evocative exceptions to this rule are phrases or lists with three parts: "I came, I saw, I conquered" uses the natural rhythm found in trinities. Listen to comics and humorists, whose deliveries often take advantage of the rhythmic properties of balanced sentences.
There is no universal agreement about which position—the beginning or the end—is the most powerful. The doctrine of primacy says lead off with your strongest statement. The recency argument says finish with your most powerful punch. Usually it's a matter of using your strongest point in one place, and your next strongest in the other.