Work backward from the moment you must move
An airport car leaving at seven needs everyone at the vehicle before seven. Allow for closing windows, bringing bags downstairs, checking the door and walking to the car. Put items already packed where the right traveler can collect them. Leave a morning-only note for anything that must remain in use overnight. Assign the final door check so the last person knows when the household is ready to leave.
Keep the things still in use on a short list
Keep a short morning list for items still in use, such as a phone charging overnight. Assign one person to check that list at departure. If a bag will travel in a different vehicle, mark that fact clearly so it does not leave early with the wrong person.
Place essentials with the person who needs them first
If one vehicle leaves earlier than another, do not put the second group’s tickets, keys or only charger in the first vehicle by default. Ask each traveler what they must reach before the bags are unpacked. On departure, read the morning list against the items actually leaving. Clearing yesterday’s checklist is no proof that today’s phone was taken from the charger. A small current list works better than a long packing list nobody has time to read.