Introductions are often the most difficult part of writing an essay, and sometimes it is easier to write the rest of the paper before writing the introduction. In any case, the purpose of an introduction is to capture interest and prepare your readers for what you are going to say in the rest of the essay.
For an essay on The Crucible, you undoubtedly have a specific focus which you will be writing about, and that is a good place to start thinking about your introduction. For example, if you are writing about how pride affects the outcome of these trials, a quote by or reference to Danforth at the end of the play when he refuses to even consider a pardon for Proctor and the others might be useful:
I will not receive a single plea for pardon or postponement. Them that will not confess will hang.... Postponement now speaks a floundering on my part; reprieve or pardon must cast doubt upon the guilt of them that died till now. While I speak God’s law, I will not crack its voice with whimpering.
If you are writing about the redemption of a flawed man, Proctor's plea to let him have the one thing he still has, his name, might be effective. Keep in mind that any quote you might use must be directly connected to the essay or it will be a distraction rather than an effective attention-getting tool.
Asking a question about whether or not your readers have ever made a mistake which ended in serious consequences might be effective for an essay which focuses on that aspect of the play. If you are writing about the lies which caused such tragedy, obviously a short discussion of Abigail Williams is appropriate.
Since this play recounts a semi-fictionalized account of a real event in history, perhaps a quick review of the real Salem Witch Trials information or something interesting about Arthur Miller would be interesting and helpful. The same thing is true of this strategy as of the use of quotations; the information must be applicable in some way to the essay.
I have attached an excellent eNotes site on how to write an introduction. Several suggestions from that site include the following:
- Start with a quote that is related to your topic, and make sure it's a powerful attention getter.
- Start with a question, perhaps a question you had yourself before you began your initial research.
- Begin with an interesting fact that is related to your topic.
- Use an analogy, but make sure it is concise and easy to understand. You don't want to get too lengthy, because your introduction should be about 10% of your entire essay.
- Try presenting a paradox if it is related to your topic; readers are interested in the unusual and seemingly unanswerable.
As long as you do the two things--capture interest and prepare readers for what you will be writing about--you will create an effective introduction.