If you don’t know what to do about setting up an introduction, try the inverted pyramid. It is a little bit mechanical, but it can help you get started in the right direction with a “working introduction.” It is always possible to go back later to add or subtract from the introduction after the paper is otherwise finished.
Think of it as a triangle with the wide end up. Start with a few general comments about the topic at hand, and then move to more specific commentary in the middle. The end, or point, should be your assertion or stance.
Each section can be a sentence or two depending on the topic and the specific assignment. Take a look at this example:
Americans probably have more pets than the citizens of any other country. (general) Just walking down the street, it is easy to spot numerous cats in the window, dogs going for walks, and even birds in cages looking out on to the world. (general, but categories mentioned) Many of the most passionate pet owners are dog-lovers. (categories narrowed) They believe in the old saying that dogs are truly “man’s best friends.” (more specific background) However, even in the dog world, there are a number of opinions about which dog is the best as a pet; some argue for pure bred dogs and others advocate mixed breed “mutts” as the way to go. (introduction to assertion) There probably isn’t one clear answer, but anyone who cares about saving an animal’s life should pursue a mixed breed dog from a pound or animal rescue if they are looking for a loyal, loving pet. (assertion)