This is an open list and is based on personal experience as recruiter for a private language school in Sicily (Italy) since 2011.
Most suggestions about the CV are based on the European guidelines (see European CV).
I would like to point out that I have had the chance to meet, interview, often even work with excellent and professional colleagues, who set the high standards my school is following.
They helped me prepare young colleagues for the job world. So make treasure of what you haven’t thought about before.