Split the group into pairs or, for a bigger group, stand in a circle. In pairs one of course massages the other, in a circle everyone can massage the person to their right. Loosen up the shoulder and neck, shake the arms, pat down the whole body from head to toes, etc. A circle massage limits the options but especially for new groups that are doing theatre sports for the first time, it is a fun occasion. Also works well as an audience warm-up.