An incredibly simple yet effective way of sorting groups is to utilize playing cards. In my class, I hand each student a card when they walk in and then use them to break the students into groups.
On one occasion, the students sit by suit. On another they sit by numbers. Or by odds/evens. Or reds/blacks. Or they form a straight. Or numbers are paired together.
It is an instantaneous way of breaking students into groups without the drama of having to “choose” partners like on the playground or having the same people sit together all the time. The students turn the cards in at the end of class and I shuffle then redistribute them at the start of the next.
How can you use this economical method of matching partners in other settings? Use it to form brainstorming groups at a meeting. Develop seating assignments at Thanksgiving. Determine who works on a new assignment. Or use it for household chores: this week, the reds set the table while the blacks clean up.
Shuffle up your repertoire of how you divide people or tasks and let the playing cards do the work for you.