First of all, when you are writing your first draft, don't spend hours agonizing over your introduction. If an idea for the introduction doesn't come to you after a few minutes of thinking, start writing the body of the essay and come up with an introduction later.
What am I supposed to do in the introduction?
The most important things the introduction does are introduce your topic and get you to your thesis statement, which often comes at the end of the introduction.
Ideally, the introduction also gets your reader's attention and makes him or her want to read the rest of the essay. It is important to think seriously about your audience and try to write an introduction that will mean something to them.
Five Introduction Ideas
A Surprising Statement, Quote, Fact, or Statistic
Though this is somewhat over-used, it can be effective. If you have an attention-grabbing quote/fact/statistic that sets up your thesis well, then it can be a powerful way to start. However, do not just drop in a quote or a statistic for the sake of dropping one in.
Example: For more than half an hour, 38 respectable, law-abiding citizens in Queens watched a killer stalk and stab a woman in three separate attacks in Kew Gardens. (Martin Ginsberg, "38 Who Saw Murder Didn't Call Police")
Starting your paper with an interesting question can work if it makes your reader curious about the answer. It can also help keep you as a writer on track because your entire paper should be addressing the question.
Example: Why do lovers marry? For centuries the answer might have been self evident, but in today's world, where cohabitation is more bourgeois than bohemian, it's an open question. (Maggie Gallagher, "What's Marriage Got to Do with Love?")
Brief Story or Example
It is possible to grab your reader's attention by telling an interesting story, especially if it appeals to your reader's emotions (fear, anger, joy, etc.). If you do this, tell the story well but do not let it get too long or else it might start to take over the paper.
Sometimes you can begin a story in the introduction, then stop the story and present your thesis and the body of your essay. You can then finish the story in your conclusion.
Example: One Christmas day seven years ago, I'd gone over to the Henry Horner Homes in Chicago to visit with Lafeyette and Pharaoh, the subjects of my book There Are No Children Here. I had brought presents for the boys, as well as a gift for their friend Ricky, who lived on the other side of the housing complex, an area controlled by a rival gang. Lafeyette and Pharaoh insisted on walking over with me. It was eerily quiet, since most everyone was inside, and so, bundled from the cold, we strolled toward the other end in silence. As we neared Damen Avenue, a kind of demilitarized zone, a uniformed police officer, a white woman, approached us. She looked first at the two boys, neither of whom reached my shoulder, and then directly at me. "Are you O.K.?" she asked. (Alex Kotlowitz, "Colorblind")
Paint a Picture
Describe either an ideal, best-case scenario or a horrifying, worst-case scenario. Either way it makes the reader want to read on in order to find out how he/she can make the good thing happen or avoid the horrible thing.
Example: Could you imagine saying the pledge of allegiance to a Confederate flag? A relic of the past that one would usually expect to find relegated to textbooks, the Confederate flag is actually alive and still flourishing in the South today. A haunting symbol of those days of slavery that many Americans would rather forget, the flag is continuing to stir up emotions in groups with opposing interpretations of history... (Galit Sarfaty, "A Forgotten Past")
Summarize the Problem or Situation
Although it is not particularly attention grabbing, sometimes it is necessary to begin by summarizing the situation for the reader. If you do this, it is helpful if you can also explain why this problem or situation is important. Keep the summary short (50-100 words).
Example: Millions of college students pursue an impossible body image. Their self-acceptance is based on having the perfect body, the ideal size, and the ideal weight and disappears once the extra pounds return. They also have trouble believing other people can accept them without that ideal body.
In their pursuit of the ideal body, they devalue the body they have and negate their unique sense of self. Their body images get in the way of their liking who they are. They do not feel a sense of integration and acceptance. (Karlene Robinson "In Pursuit of the Impossible Body Image")
Reminder: The most important thing that your introduction does is get you to your thesis; never lose sight of that fact.