I have colored poker chips in my classroom. There are 4 colors, so take those colors and line them up alternating all 4 colors and then write a number on one side for the total number of seats you have in your largest class (for me it is 22). Flip them over and write A,B,C,D,E on the other side while alternating colors. Let the students draw when you make cooperative groups instead of counting out numbers.
When you need to make groups, count how many students you have and remove chips higher than that number to give you groups of 4 by color. Use the numbers to make groups of 2 (1&2 go together, etc.). Or you can make larger groups using the A,B,C’s.
Plan ahead and this saves tons of time on groups. I use this all the time. It is adapted from Marzano’s classroom Management that works.