By either utilizing the library or interviewing experts on the field. Here the author puts into consideration the audience, the topic and the purpose of writing the essay.
Below is an example of good and bad thesis statement regarding the same issue.
Good: “students’ textbooks should be swapped with tablets or computer notebooks.” Bad: “students’ textbooks might be swapped with tablets or computer notebooks.” The good thesis statements persuade readers to back replacement of student’s textbooks with tablets or computer notebooks.
Bad: The Federal government should recognize civil unions.
The real counterargument statement has the reason why the federal government should recognize civil unions, an aspect lacking in the wrong counterargument. The author should defend his/her arguments via practical evident, facts and should back his claims with references.