1Research your topic. Once you've got a vague idea of what you'd like to write about, you'll need to research your topic. This is a vital step for writing an argumentative essay. You will need to be very well informed about your topic and the arguments surrounding it, in order to be able to make a strong, coherent argument. You can find books in a library, search the internet for reliable sources, and read back issues of newspapers and similar media to get information about what you're arguing. If you can, find an actual expert on the subject and ask them if they would be willing to do an interview.
During the course of your research, you will want to collect as much evidence as possible. Statistics, charts, data, and empirical evidence will help you make your argument but also give you fodder for criticism of the other side. How to use this evidence will be discussed below.