There are 40 cards in all. You can put these on a ring and just pick one randomly to call out to groups. You can also randomly pick one to give to each group so that each group has a different way to find who goes first. Of course, at the beginning of the year when you are setting your routines, you'll teach your students what to do if they need to have a tie breaker or if no one in the group satisfies the criteria.
I've also created 5 spinners that can be used in the same way. Kids use a paperclip and a pencil to spin the spinner. These spinners can be put on a ring and hung in a convenient location. They could also have a magnet applied to the back and put in a handy dandy spot so your students can get to them.
I've also created a teacher card that has all 40 ways on one card so it's at your fingertips; you'll see it in the download.