Establishing a good personal rapport with students is one of the key ingredients of successful EFL teaching; but to do this some background information is needed.

A tape or video of the song Getting to Know You from the musical The King And I makes a good introductory listening exercise or background sound-track.

Try setting the students tasks which require them to talk to each other in as informal a guise as possible. Give them "tasks" to complete - e.g. find another student with the same musical tastes as yourself; or different ....xyz.. - the possibilities are endless.

Alternatively, try asking students to find out all they can about each other and then ask each student to introduce and share what they have learned about another student's background.

The ice must be broken as quickly as possible, and to this end it can be helpful if the teacher shows him/herself as approachable as possible. By showing his/her face at socials a teacher rapidly gets to know the students' interests and characters, and can (to some extent) then plan successful lessons around the students.

Hope these suggestions help.... Good luck!