There are a few ways that you can "hook" your reader into reading your essay. First, you could ask an intelligent rhetorical question that focuses in on the problem that you will be discussing. Be careful with questions, though, because if they are too simple they will not be effective. For example, don't write, "Don't you think that teenagers should have jobs?" Instead write, "Wouldn't society be better if all teenagers could get off the streets or away from video games if they had jobs to go to after school?" This second question brings up some interesting issues right at the start. Another way you could write a hook is by using a brief narrative example of a true situation that may have happened to you or a friend. That way, you can establish some credibility by relating a real-world experience that the reader would understand. Also, look at the main points that you will be using to persuade your reader to side with you on your position and take some ideas from those to write your hook. That way you will also be able to refer back to it later when you are presenting your arguments.