My actual exams are perfectly done (invigilators are so professional, they have everything at hand and are really quiet and don't walk around, instead they just position themselves around the room).
The most annoying thing for me is just before the candidates called into the exam room, where people are hurriedly talking to their friends about a specific topic like "omg omg if it's this, what do you do". just stfu and let others (like me) remain calm and away from your last minute babble -.-