How do I write a conclusion?

Firstly, make sure to never add a new point in the conclusion! A conclusion should be a neat summary of your argument, with a punchy line at the end if possible. Reference your introduction as you write your conclusion, as often you are just reiterating what you have written in your essay to clarify your points to the reader. If the essay has been written correctly, the same points should have been laid out in both the introduction and conclusion, with just a little more expansion!