Amigos del Reloj "Friends of the Clock"
This PDF document will be a very helpful classroom management tool. Use this tool to pair students up for partner work.
To set this up at the beginning of the school year, I line up half of the students and have the other half face the first line of students. As one line rotates, they write their partner's name on the time you indicate (you can have up to 12 partners). Tip: make sure everyone is on the time you indicate and have them wait until everyone is ready to rotate to their next partner / time. If you have an odd number of students, you can have the student without a partner write "free." When it is time to use the clock for a partner activity, the person with the "free" partner can choose to work with any group, if no one is absent that day.
You can also have pre-assigned partners for any time you select.
Bonus: this tool allows students to practice telling time in Spanish every time you want them to work with a partner. They will ask "Que hora es?" Your answer "Son las tres." tells them what partner to work with for that activity.