If you are flying with young children (or indeed the very elderly) make sure everybody has been to the toilet before getting in the aircraft.
My first post ppl flight with Mrs g45 and g45 Major (aged 8) and g45 (aged 6) . ATC at EGPH doing their usual fine job of slotting us in between an arrival and a departure I was lined up and waiting for the arriving aircraft on 24 to vacate with an easyjet 737 on a four mile final. Arriving aircraft vacates. ATC says "g45. With a left hand turn out cleared take off 24" immediately followed by grow 45 minor saying " Daddy. I need a wee"
Also make sure sick bags recomended by Saab Dastard are handy and not tucked into the bottom of your flight bag - but thats another story although it involved g45 minor again.
g45