Sydney International Airport expects 5.8 million passengers during the Christmas and New Year period, with airports nationwide anticipating record numbers. Former flight attendant Nicola Dale provides travel tips including checking in online, packing light, keeping essentials like passports and chargers in carry-on luggage, and staying hydrated. Travelling on Christmas Day can offer lighter loads and festive experiences, with some flights featuring decorated cabins and carol singing at 35,000 feet.