The good ol’ fashioned “You all meet in a tavern, answering a poster offering gold for help…”? The action-scene, “You’re all engaged in mutual mundane task, when suddenly a band of thugs/goblins/whatever bust in looking for the plot coupon and chaos breaks out”? The “Elder Scrolls classic” - all being prisoners thrown in together? Tie it in to a character’s backstory and let them lead the other party members in?
What have you found interesting or successful, and why?
My favorite one-shot I ever played in began with
“You wake up. It is a dark and stormy night. You realize you are dead.”
The group had all been raised from the dead by a mediocre necromancer, and the plot went from following his commands, to breaking free from his command and earning our freedom.
Somewhere on the Sword Coast there is still a little pub between towns that’s staffed by two skeletons, a ghost, and a ghoul.