This is a management tool I use to randomly select pairs of students for partner work while still allowing me to separate students who do not work well together. Among other uses, it can be used to pair students by achievement level (i.e. high/low reader).
Template includes three different color combinations each for classes of 20, 22, 24, 26, 28, and 30 students. If you have an odd number of students, choose the template with one extra spot. I usually allow the student who lines up with an empty space to choose which pair they would like to join to make a group of three.