Editors note: This is for Ms. Morgan who hates it when this happens. Now you can point to it being bad manners!
Some member of the household always goes to the door with the departing guest. The guests who will be remembered gratefully are those who express thanks for a pleasant time and take themselves off without due delay. Long chats in the hall or doorway, while other guests are wondering what has happened to host or hostess, are sure to take some of the shine off a party.