You may have seen that you can create your own groups through the CP function, which is perfect for after school clubs and sports teams. Teachers can create these too and once they have been inputted you will be able to assign messages, calendar dates and send emails and texts to the group or contacts of the group.
Go to CP > Groups and add your groups here. Add the name of the group and go to the tab marked 'Members' to add the individual users. If your group has a number of adults attached, you may want to select a main user.
As an administrator, you will notice the 'Hide from Users?' checkbox. This is very useful as you can create groups of students that do not necessarily need to know that they are part of said group. For example if you need to contact the parents of children on Pupil Premium, or who use an Epipen, you can create these groups here and the group will not appear for the children in the group.