The presentation of a good argument has a number of important components. Having your facts correct (and sourced), the tone and timbre of the argument, and understanding the tools of debate; in particular, having an understanding of fallacies.
Similarly, understanding an opponent's argument and rebutting it requires similar components.
Here at the Daily Kos (and in political debate in general, truth be told), I see an awful lot of misidentification of fallacies. Quite often, folks can see that an argument is logically weak, but they don't correctly identify why it is a weak argument. This lessens the quality of the rebuttal.
So - do you know your fallacies? Let's start with a little quiz here.