You might also encourage your parents/fans/players to learn the laws before the criticize the referees or demand a card for an opposing player. Part of my irritation last night in Chapin was how ignorant the fans were.
A few seasons ago I was AR for a game involving our local club. From the players side a could hear our club's parents yelling about offside calls. After the game, as I was leaving, I took a moment to call to some of them and explain the offside law to them. They were surprised at how different the actual offside law is from what they thought it was.
Sometimes I think parents should be offered a brief workshop on the laws of the game, and players certainly should. My daughter has been a ref for several years now, and my 11-year-old son will be taking the Grade 9 course the next time it's offered.