Aside from foilists being argumentative (yes, we are) and epeeists being slow and old, I think my favourite was the use of screaming to persuade the referee that both his judgement and the electric box might be wrong and the loudest scream denotes the winner of the point.
One of the competitions I was at recently was being held after the British Ranking Championships for U18 (a serious business for all involved) for which the Women's Foil final became the most incredible competitive display of mountain lion impersonations!