British Airways state that staff are only allowed to be licensed to serve on three
different aircraft types at anyone time.

British Airways will promote to purser; looking after a particular cabin such as
First class or Club.  Promotion from purser to Cabin Service Director will give
control of the whole in-flight service.

The most successful Cabin Crew tend to be outgoing

Under UK AOC (Aircraft Operators Certificate) it is a requirement that you are
fluent in the native language of your base.  For example, if you were hoping to
be considered for a Cabin Crew job stationed in Athens then you will need to
prove that you can speak Greek fluently. 

Rights to live in the country you are stationed is a requirement of UK AOC,
but it is important to add that all EU citizens have rights to live in any other
member states.

You must be living or prepared to move within one and a half hours of your
base (less in congested areas) for most airlines, but requirements do change
from airline to airline.

Prior to boarding the plane your purser will brief Cabin Crew on their
responsibilities during the flight and more importantly checking their
understanding of safety and emergency procedures.

On board the flight work includes safety equipment checks.