Gladly!
The objective function you're optimizing for is safety, which in a social setting -> the opposite of self-consciousness*. ie,
You want your guests to be able to drop into their bodies, the sensorium, and so together spontaneously the moment**.
Countless of ways to do this; here are a few:
1. Classic host trick:***
Notice anyone whose posture suggests they're stuck in their head, and ask them for help with a manual repetitive task, like chopping or serving drinks (then thank them for it, sincerely). Put them in charge of anything, really, that will set some skill (however banal) off to advantage as a contribution.
2. Movement practices, sports, hacky sacks, barn raising --any kind of physical coordinated collaborative thing with latency and stakes. Can be low stakes! But needs some skin in the game.
One of my favorites is square dancing. Squares are all a little different, each a real time group puzzle that is not *hard*, but is JUST tricky enough that figuring it out with seven new friends is gratifying when it works ("We did it!").
3. Facilitated sharing.
Tricky to get right & make safe**** (circling ain't it!), when people see they are seen / understood / accepted / appreciated by the group, they get high (/horny).
4. Cuddle / make out / start dancing with the least conventionally attractive woman in the room. Makes everyone remember they too are lovable (which in turn makes everyone much more obviously lovable).
5. Make sure everyone brings something to the table, and what people are bringing to the table is KNOWN. Good and bad, actually: you want to elevate what is impressive about shy people, and gently tease (moderate the status-grabbiness) of those of us who are more aggressive about advertising our gifts, to make the reputational economy just. (And when people are mean / neggy you spiritually cut them, so people see they are being protected from fuckery).
6. When all else fails, you can fall back on time pressure to force folks into the present. I've never done this but it would absolutely work:
Get some QuatProps(.net) --which permit even very handicapped uncoordinated people to learn to juggle-- and set a rule where you have to leave the party inner sanctum when your balls drop (/come back when your balls are back in the air).
* And that's the primary function alcohol serves: it's a brute force way of making people forget their "self" so they can be themselves more easily.
** In Fristonian terms: attending principally to bottom up rather than top down priors. In neuroimaging terms, you want the default mode network shut down. In interpersonal synchrony terms...well you want to max out potential for the interpersonal receptivity and warmth that gives rise to people 'syncing up' (which is measurable, as it turns out).
*** This is a classic because it is a twofer mechanistically, both holding their attention outward (lest they cut themselves) AND reifies that they are contributing.
**** This is quite literally how sex cults in ISTA-world get participants high as a kite (think ~100mg MDMA) without drugs before anyone takes their clothes off. I DO NOT endorse sex cults, but we can learn from them.