Go to the bar, get a couple of drinks as if it's your shout, walk over to the set you want to open as if they are the people you came there with, not noticing that you don't know them, if you get what I mean, plonk the drinks down on the table and continue a ridiculous story in which you have your pants around your ankles in a public place.

Look up after mentioning your pants predicament and realise you're not a part of their group, give them a "WFT? Who are you guys?" look, closely followed by a "Well you'll do" look and continue the story.

EXAMPLE:

"So there I am in the middle of the bar with my pants around my ankles about to throw this dart, right"

"I knew I had to get it spot on or I was losing my undies next" blah blah blah then you fuck them all.

Good for opening sets of 3 or more where the conversation isn't raging, the other drinks you have are a visual FTC and if all goes well you can call your wing over. Requires a bit of a "fuck it" frame, and gets the first thread of the conversation going without even opening.

I've tried it twice, succeeded twice. Give it a go.