I think ice breaker games rarely work for anything. They are often tedious.
They are utterly tedious! We have an organizer here who also does coaching in workplaces. His "Let's stop the milonga to play a game!" moments shatter the evening's flow and mystique.
Now, I'm going to resort the the much loathed writing construction: the list.
As an editor of 30 years, I'll say that the list is loathed in non-technical writing only. In technical writing, it is the gold standard for organizing information.

Forums like this one are essentially amateur technical writing platforms, whatever people might think.
If you are the studio or organizer, suggest name tags.
So simple, yet nobody does it. I think I'm going to buy a pack of sticky tags, wear one unbidden, and leave them and a pen near the entrance.
Have some cheap free snacks, preferably in a quieter part of the room or gathering [...] Do pay attention to volume of music. It needs to be just loud enough to dance but no louder.
I think the best compromise is to have a dance floor near the speakers and a break area away from them, in another room. I know some people dislike the separation because they believe it forces commitment to dancing or taking a break . . . but that's in their head. As much as I adore the cabeceo – and I do – there's a long tradition of people who are already having a conversation when excellent music starts enjoying the privilege of asking for a tanda as part of the talk.
The cabeceo is for the room with the dancing. Replacing a social barrier with a low physical and acoustic barrier seems like a fair exchange.
If there is a possibility, encourage people to NOT dance with the same partner for more than two dances in a row. That may require leaving a little time for people to leave the floor and find new partners after each of the songs. Yes... I know. This is so not Tango where a three dance Tanda is the norm. Maybe you can do it if you announce "please, try to mix up your partners. We will not play in Tanda order" for a half hour or show. Or maybe this would drive away Tango dancers. But... well... the three dance Tanda tradition is a feature of tango that almost certainly results in less social mixing.
This is the only one I'd object to.
The aforementioned business coach tries these sorts of things from time to time. NOBODY likes it. The old guard find it an affront to tango tradition. The newcomers it's supposed to benefit find it chaotic.
I think that in tango, the best fix is three-piece tandas instead of four-piece ones, and longer cortinas. People sometimes grumble about those things, too, but they tolerate them, and these measures do encourage mixing.
Ok.... then "Chacarera". One points out when he started he didn't like that because he didn't know how to dance it. Yeah... great, add something no one knows how to dance.
Chacarera is a terrible icebreaker. People see this rigidly structured dance with lines and rules, one they've never learned, and feel utterly excluded by it. Tango is already hard to learn, and it's really three dances in one – tango, tango-vals, and milonga – each with its own substyles and forerunner dances (canyengue, candombe, etc.). Slathering on
another dance related only by regional origin, not by musical tradition or steps, is intimidating and unwise.
"It's Argentine, so it belongs at the milonga!" is a big pile of . . . whatever. Not many AT dancers care all that much about Argentine culture. For them, tango is a dance and a musical style. They're not going to go all-in for other Argentine dances, start drinking Malbec, learn to say -ll as -j, etc. simply because they dance tango.
If organizers and DJs want to break the ice, they should play a few sets of cumbia, salsa, swing, and other music that allows freestyle dancing, and that feels like music a person might dance to at a nightclub when they go out to, you know, meet people. Anybody can clumsily two-step to such a tune, and if most of the crowd is equally mediocre, much ice is broken as the barrier of level comes down.
I don't think their solutions are going to be universally helpful. Few are.
My mantra since joining these forums has been "Everything varies by where you are."
There
is an "international AT scene" that exists at encuentros, festivals, and marathons for the jet set, but it is characterized largely by its absence of anything that would offend anyone, and it isn't a community. It's a least common denominator of polite dancing as oppose to a spicy mélange that the locals adore but that visitors find tricky. Involving people locally means doubling down on the spicy mélange even when it isn't what you'd find at a festival somewhere, because your goal is to engage and keep locals, and build a local community where people know names – not to onboard locals into an international scene in which few of them can afford to participate anyway.