A Razor Keen
First and foremost, to write effective satire, you should never state "This is satire" or words to that effect. By doing so, you have already lessened the impact, dulled the cutting edge of the razor, and given your audience the opportunity to turn a deaf ear to your voice.
Juvenal, a Roman poet who lived almost 2000 years ago, wrote several poetic pieces on then contemporary Roman life. His works were mostly satirical in nature and he is credited with coining the phrase "Who will watch the watchers?" With that, satire was born!
There are many elements of effective satire, some of which include wit, irony, derision, humor, ridicule, and cynicism. For a more in-depth discussion of a definition for satire, see "On Satire".
Elements of effective satire
Wit: a keen, astute perception and the ability to think through a topic or situation clearly and critically. Wit should be seasoned liberally with cleverness. As Mary Worley Montagu said, "Satire should, like a polished razor keen, Wound with a touch that's scarcely felt or seen." Your wit should be biting, razor sharp. This is the primary ingredient for exceptional satire. After targets of opportunity of course.
Double-entendre—the art of saying one thing and clearly meaning something deeper or different can be utilized often. Most of us can do this frequently with off-color, bawdy, sexual jokes and references. Can you do it with politics or in a diatribe over a public figure? The phrase "great men are not measured soley by the size of their desk" comes to mind.
Humor plays a large role in getting your audience involved. Feel free to be funny, but try to avoid being just plain silly. Humor should reinforce your point. Without a point to convey, satire devolves into meaningless drivel.
Outrage. You should identify the problem, offer a solution to the problem and be perplexed, annoyed, and perturbed that everyone else, or at least the object of your satire, is too dense to see the validity of your solution. Either that, or he or she lack the public compassion to care, the intestinal fortitude to act or the strong, upright moral fiber that you possess to stand fast in the wake of crumbling values and potential disaster.
Ridicule is the next logical step after the outrage. Feel free to lambaste foibles, folly, and fool-hearted stupidity wherever you see them raise their hydra-heads. A word of caution: the satirist must beware that he not be "hoist with his owne [sic] petar" (William Shakespeare, Hamlet Act III).
Cynicism is the ability to look askance at something, or someone and offer an opinion contrary to the status quo and is a great tool for satire if used sparingly. Too much and it can too often sound like nothing more than bitterness.
Sarcasm should be used sparingly in writing satire and is much better suited for verbal communication since inflection, timing, and gestures play a large part in conveying your true meaning. Also, an overuse of sarcasm can lead to a sense of distrust in your audience and can lead them to lose their suspension of disbelief.
Details, details
Much as in other forms of writing, with satire, you don't want to tell your reader someone is an ass, or something needs to be changed. Show them.
For instance, in a non-satirical piece about a rainbow you would not say, simply, "the rainbow was beautiful" and leave it to the reader's imagination to fill in the details of your specific rainbow at the specific time and location in your story as viewed by your protagonist, antagonist or narrator. You might say "the red was vibrant, fading into an orange the color of fire" or "the hint of a rainbow highlighted the eastern sky, signaling the welcome end of the vicious storm." You would want to present something that provides some insight into how your readers are supposed to view your rainbow.
With satire, you want to target the same level of detail:
"The world has gone mad! Mad, I tell you! Electronic devices are taking over. We have computers that cook our food for us, drive our cars, tell us when 'a door is ajar.' A door is not a jar… it's a door. Stupid machines! We have machines that entertain us, keep us alive for the entertainment of others, answer our phones, flush the toilets when we forget and vacuum our floors. It all goes back to that guy that invented fire. Probably the same guy that invented the wheel. Damn inventors! I've had it! No more inventions! No more inventors!"
Obviously, it is not desirable, nor currently legal, to exterminate inventors, and equally not desirable to eliminate all inventions, past, present and future. The point being, there are several elements of satire in the above paragraph: exaggeration, a sense of outrage, a bit of a diatribe, a suggestion to "cure" the problem, and details that indicate the author's disdain for machines. Behind this, though not obviously stated, is the underlying lament and most probably the gist of the diatribe, that machines are interfering with our enjoyment of life and our pursuit of happiness.
Irony, "a technique of indicating … an intention or attitude opposite to that which is actually or ostensibly stated" (dictionary.com), is another hallmark of satire. Imagine the above piece posted electronically on a forum or blog site using the very object of the author's cynicism to produce, display and allow others to read those words. That would truly be ironic.
Take any situation, say a presidential candidate's or a hopeful's speech and extrapolate something they say or do to the level of absurd. Think of Ludicrous Speed from "Space Balls"© or the "What have the Romans done for us" bit in Monty Python's "Life of Brian"©.
Satire is not necessarily funny, though. For example, Jonathan Swift's "A Modest Proposal For Preventing The Children of Poor People In Ireland From Being a Burden To Their Parents or Country, and For Making Them Beneficial To the Public" is definitely not funny, and not for the faint of heart, but is definitely absurd and is satire at its finest.
So, how do you get started? Given the boundless opportunities that the human condition presents, may no faux pas escape diatribe, no gaffe be veiled, no public fools go unskewered.
Perhaps, Ambrose Bierce offers the best summary in "The Devil's Dictionary": "SATIRE, n. An obsolete kind of literary composition in which the vices and follies of the author's enemies were expounded with imperfect tenderness. In this country satire never had more than a sickly and uncertain existence, for the soul of it is wit, wherein we are dolefully deficient, the humor that we mistake for it, like all humor, being tolerant and sympathetic."