We have to put out the candidate numbers, question and answer sheets checking each name against a master copy. Write up the boards with the exam number, subject and length.
Watch the pupils coming in checking water bottles have no labels, equipment is in a see through bag, etc. There are lined up in row/number order by teachers.
Listen to/read out an announcement and collect in any prohibited materials. Also, new this year, make sure watches are removed from the wrist and placed on the table. The lead invigilator will then start the exam and write the start/finish times on a board.
Whilst the exam is going on you watch for cheating, communicating, etc (rare to never in my experience) and requests for paper, toilet, equipment, tissues, etc. We move around the room at roughly 15-20 minute intervals.
At the end (no times are called out) we collect answer papers, then question sheets/inserts, then candidate numbers. Then the lead invigilator will dismiss them row by row.
Can be boring but I usually amuse myself by working out the percentages of pupils - left handed, blond hair, glasses, house ties, etc!