One thing my Dad taught me was how to win an argument. Not that he was a great debater. Looking back on it, I don't think he was. But he always won arguments with us, and, eventually, I figured out how and why.
Discussion is intended to raise and collect facts and opinions around a topic; to educate, and, sometimes, to entertain. Debate is intended to establish the strength of one position over a competing and opposing position. (And, as rhetoric, sometimes to entertain.)
For the sake of argument (you see what I did there? :-), I will say that argument is distinguished from these two by the intent to establish dominance. Dominance sometimes in time, in inkspace, in mindshare, or simply in status.
1) To begin, to win an argument there has to be an argument. This is easy to create. Wait for a statement to be made, or an opinion to be expressed, and then take the opposite viewpoint. (In our family, this is known as "being a larry," in memory of one who felt that a conversation was not complete without some controversy.) It is not necessary to feel that the opposite viewpoint, which you are expressing, is right. In fact, it is possibly best if you don't have any strong opinions, one way or another. Strong emotional attachment to one side or the other may lead you to make mistakes in the heat of verbal (or written) "battle." Having no strongly held opinions also allows you to switch sides easily, if, in the worst case, your opponent admits that you have made a valid point, and comes to agree with you.
Never admit that you don't care, of course. Always assert that you feel strongly about the issue, and are trying to establish truth, or some other factor of benefit to society at large.
2) A major factor in winning is being specific. Or, rather, forcing your enemy to be specific. Ask for an example. If your opponent gives a good example, say that you don't understand how it supports his position, and ask for another. Ask for more details of the example given. Keep on asking for more specifics. At some point your opponent will make a weak statement. At that point you attack the unsound remark. It does not matter that the utterance is not central to your adversary's theme: it is a weak point that can be exploited. (This is similar to the infosec principle of the attack surface.)
3) An additional technique is to divert. If your opponent's position is strong, you don't attack it directly: you attack something else. (Attack surface, again.) This is enshrined in the advice to all new lawyers: if the law is against you, argue the facts; if the facts are against you, argue the law; if the law and the facts are against you, raise your voice. If your adversary is winning, essentially you move the goalposts, by starting to argue something that sounds like it might be related, but really isn't central to the original discussion.
(There is an excellent example of this in the movie "Thank You for Smoking." I can't recall if the book expresses it as clearly: both book and movie are great, although stress different aspects. But the movie is full of examples of deflection in debates and arguments.)
4) You must always attack your opponent. Passion, and particularly anger, may give people energy, but it also makes them careless. In the musical play "Billy Bishop Goes to War," there's a line that says, "You're part of a machine, so you have to stay very calm and cold. You and your machine work together to bring the other fellow down." It's the same in debate and argument: you are part of a process, so you have to work the process, and keep calm while doing it. (See point 1 again.)
But you have to be very careful about how you assail your adversary. Simply calling him or her names leaves you open to charges that you are mounting an ad hominem attack (attacking the man, and not the argument). It is almost automatic that if you are accused of ad hominem attacks, you lose. In fact, it is best that you take every opportunity to take personal offense at anything the other person says that might remotely be construed as obnoxious, or even just disagreeable. You can then accuse your adversary of an ad hominem attack, pre-emptively. It doesn't matter if you really are offended by what was said: remember that the objective is to make your opponent look bad, not to establish the validity of what they said.
If anything you say is challenged as offensive, deflect via an accusation of an ad hominem attack, or say that what you said or wrote was only "for effect," or that your words have been misinterpretted or misunderstood. (Possibly the best ever example is the statement, "That depends upon what your definition of "is" is.") If opponents persist in accusing you of objectionable attacks, divert by asking for specifics (as per point 2).
5) Keep the argument going. It need not stay on topic, indeed, it's probably best (for you, not the discussion) that it doesn't. (Remember the pursuit of irrelevant specifics and diversion from points 2 and 3.) The objective is to dominate: to achieve the maximum filling of time (in a cocktail party conversation), inkspace (in an online or written discussion), and mindshare. Your name or (expressed) opinions must be repeated as many times as possible. If at all possible, entice multiple adversaries into the argument. That way the back and forth will look like A-B-A-C-A-D-A-B-A-E-A-C-A-F-A and A is obviously dominant.
6) If you are losing, quit. There is no point in pursuing a topic if you aren't winning, or, at least, not obviously in the wrong. (This is why it is best not to care too much about the point of the argument itself.) You can simply stop, or possibly accuse your adversaries (generally losing requires that multiple people consistently support your opponents) of "blinkered, philistine pig-ignorance" or a reasonable facsimile thereof. (This possibly gets you one final point before you leave.)
There is always another argument and chance to start again. (See point 1.)
Ooohkaaay.. I'll bite.
Now, for the sake of argument (see what I did there) - why would you want to DOMINATE anyway? I accept that discussion is necessary to learn - I like to discuss too, and given that the honourable opposition is of roughly equivalent strength, I even like a debate. But to DOMINATE anything - well, I don't get why one would want to do that, as clearly nothing the honourable opposition says if of any interest to you other than to rebuke and - dominate. You're not learning, so why the fuzz? Can you elaborate?