The introduction should be forceful and powerful and set the tone for the rest of the document. A bland opening implies that the rest of the paper will be replete with a lot of "blah, blah, blah" -- which won't persuade anyone to do anything but rush through the document.
This technique relies on the common sense of the reader. For example, "Drinking and driving causes driving fatalities -- and you drink and drive -- so you are endangering your life and the lives of others by drinking and driving."
This is an appeal to the selfish side of the reader and addresses his best interest. "If this price increase is approved, you will have to pay 20 percent more each month."
An appeal to emotion triggers feelings and sentiments. "Animal research involves the torture and murder of countless innocent little animals who are cut open, experimented on and then discarded like disposable gloves."
This relies on the reader's sense of right and wrong. "Can we just turn our backs on young women who are kidnapped and sold into slavery? Can we just pretend that nothing is wrong?"
This appeal relies on the credibility of an authoritative figure. "The Surgeon General said," "the engineers at MIT recommend," "Harvard Law Review states."
Few techniques are more persuasive than statistics. "Twenty-five percent of the patients never recover." "Every three minutes, a robbery occurs in the U.S."
This shows that you have evaluated all of the information. "Although some people think it is a harmless procedure and the effects would be minimal, it is an unnecessary risk driven by the potential for profits, and can greatly diminish the patient's quality of life."
This "what if?" technique is used to connect the reader to the issue. "Suppose it happened to your child?" "What would happen if your elderly neighbors were conned by this scam artist?" "Can you imagine never being able to go home?"
The closing should drive home your central point in a way that is compelling and leaves a lasting impression on the reader. "In 10 years, we will be out of power (or water, money, etc). We must act now before it's too late."