According to "The Purposeful Argument: A Practical Guide," authors must "resist easy generalizations of other views and instead generalize them in dignified, respectful terms"(139). Authors must also "listen closely to local voices" to truly understand different viewpoints"(140). You should also fairly summarize opponents (141).
All About Counterarguments - A page from George Mason University
Counterargument - A page from Harvard University
Rebuttal Sections - A page from OWL Purdue
Acknowledging Counterarguments - A page from Cleveland State University