Teamwork with a choice.
Let students choose their partner for work time or a project. This reward is incredibly easy to implement in any classroom, regardless of age. Many times, classroom seating arrangements ensure students who are overly friendly sit farthest apart and academic partnerships are data-driven. This way, students get to forge their own academic partnerships.
When a student has enough points, they get to choose their partner for a specific activity. Or require that both students have earned enough points to claim this reward in LiveSchool.