I'm not sure that you need to do so. I agree that 'you seem really upset' can easily turn into a meta-argument, subtly disqualifying other participants by shifting the focus of discussion to their emotional states and thereby discounting their substantive contributions. In politics this has become practically institutionalized.

I'm a huge fan of Deborah Tannen, not least because I grew up in a household with a lot of verbal and physical aggression so I am painfully aware of how awful arguments can get and why arguing is soften a one-way street for the participants. and after studying her work I found some techniques that seem to work well during face-to-face disputes to de-escalate things without going passive-aggressive. the downside is that t's time-consuming and hard work.

If someone is yelling at me and it's something more than some momentary misunderstanding that can be established and then set aside, then I just let them yell. After a while the lack of reply leads them to run out of steam, at which point I ask, politely, whether they're finished. Maybe they are, or maybe this unleashes another tirade. So far nobody has offered a third one :-) Once they say they are finished, now I have some time to talk - because they said so themselves. And instead of arguing with them or expressing my own view, or characterizing their emotional state (even positively), I try to summarize their complaint as fairly as possible, eg 'So you're saying that after I went into the kitchen to cook dinner, I set your hose on fire and burned it to the ground - is that correct?'*

I try to articulate the person's basic complaint in full, while ignoring any ancillary stuff (eg remarks about why I'm a bad person or that my mother wears army boots or that the person doesn't care for the horse I rode in on either). The point of this is to build agreement with the other person about what they said. Although I may go on to dispute it, this shows the other person that I did actually listen to them, and that I paid sufficient attention to what they were saying that I can be trusted to accurately report their own claims back to them. Sometimes it turns out that I've failed to understand something important - either how much they cared about something or some actual fact that I got wrong, so I might have to concede the argument at this point, or concede some part of it. That's OK; the point of this is not to win, but to bring an end to the conflict, and if that end disadvantages me that's my problem.

If I am going to disagree, there's two different ways that could happen. If it's about some factual issue, then I try to go back with the other person to before the dispute arose, and establish the last thing prior that we do agree about, in the same way that I secured their agreement about the basic content of their argument. This allows us (not me) to identifying the point where our experiences diverge. Maybe it's a simple misunderstanding which could then be cleared up, or maybe it stems from some difference of opinion; in the latter case I outline as briefly as possible what I thought that was different from what they thought. If they attack me for that I accept it, but reiterate that that was the opinion I held at the time, right or wrong, and show how it informed my subsequent actions/beliefs/whatever. That part usually goes smoothly because most people are familiar with the way large consequences can flow from small differences. The aim then is to identify the smallest difference that existed, before the consequences became significant, and work with the other person to understand how it arose. Making the point of disagreement as small as possible usually allows the conflict to be made smaller as well, to the point that it can be resolved without the 'losing' side having to feel humiliated. Even if I was right and the other person was wrong, I try to pass over that as quickly as possible and ask what I could do differently in future to ensure the situation does not recur.

The other sort of disagreement is one of conflicting aims rather than conflicting narratives; we're in conflict because we want different things, or both want an exclusive right o the same thing, or because of some fundamentally different belief. In this istuation I try a similar approach - get the opponent's agreement about my attempt to fairly summarize their premises, then articulate my own premises. Even if my opponent rejects them utterly I just accept that, but state gently that my premises are as firmly held as theirs, and try to articulate (and seek agreement for) what the contours of the resulting disagreement will be, ie that we may not be able to resolve the dispute, but we can minimize its scope, rather than attempting to win by throwing in other irrelevant stuff, up to and including the kitchen sink (a phrase which I feel sure originates in the accusation that not only is one party in a marriage having an affair or doing something equally bad, s/he also does a terrible job of washing dishes). This is of course even more time-consuming, because the conflict hasn't been resolved, but by gradually (and mutually) whittling it down to a minimum number of irreconcilable differences, and if possible, quantifying the value assigned to victory or loss (eg 'So you are saying that you will only feel satisfied if you are allowed to burn my house to the ground in turn, yes?'), it allows for letting the emotions out slowly in the same way as you'd let the air out of an over-inflated balloon, rather than having it pop (resulting in irreparable damage) or go whizzing randomly all over the room (with unforeseeable consequences, eg things getting knocked over). Although you're still in conflict, it's now a cooler conflict than it was before, and importantly, your opponent acknowledges, however grudgingly, the fact of your agency and your right occupy a conflicting position. At this point you can start negotiating approaches to resolution (eg going to court) or containment (eg agreeing to kick the can down the road, something countries often do over disputed territories where neither side wants to give up a claim but they don't actually want to go to war over it, so they agree to disagree).

I think that one of the primary difficulties for us as a species is our capacity to become addicted to particular hormonal experiences; our capacity for narrative in many ways serves the purpose of generating the release of hormones in predictable patterns, and it could be argued that ritualized activities or formulaic stories are a way of domesticating and channeling that. The best way to deal with someone else trying to make you into the villain of their personal story is to become familiar enough with their story that you can tell it back to them in a manner that they recognize. By identifying the driving factors between different actors and distilling the basis of the ensuring conflict to the most fundamental identifiable form, the basis for resolution (or at worst, mitigation) often becomes clear.

* I would like to point out that I have never set anyone's house on fire and you could totally trust me to cook dinner. This example is fortunately drawn from imagination rather than experience.