How do I structure a good introduction?

I've foung the best way to structure an introduction is to use the (upside down) pyramid method. You open with a broad statement that links to the general topic you'll be covering, followed by a more pointed statement relating more to the question, and finally finishing with the point your essay will be arguing in support of. In between, it's a good idea to set up a little bit of historical or cultural context, and briefly introduce the writers and texts you're looking for. Essentially, your introduction should be sneak-peak map at your essay as a whole.