Write on a bit of card...
'Family kidnapped by ninjas
need $ for karate lessons'

Works a treat. I just try to be hilarious all the time even the wardens laugh at me. Be entertaining without being threatening it goes down great. I pretend to play air guitar & get right in to it sing the notes daa naaa naa da naaaaaa naaa the worse I sound the better it gets I don't have a musical bone in my body people just like a tryer I suppose.