You may think you know the rules of squash but do you??
Check them out here: http://www.worldsquash.org/rules.html
Download a copy and keep it in your squash bag for a bit of light reading between matches.
Also, what about a bit of referee practice at the Friday night 'Club Night'?
Anyone not actually on court playing grab a scorecard and referee a game.
Any contested decisions to be discussed calmly between referee and players as a learning exercise.