Years ago, my mother told me about a beautiful tradition the Irish did on All Souls Day.  They would place a bowl of water near the hearth (fireplace) as a symbol for the holy souls to have a drink of water while in purgatory.  It seemed such a lovely thought for the simple Irish peasant as a way of showing their faith.
I love to read about what the Faith of Our Fathers did years ago. Remember when a man would tip his hat as he passed a RC church, a woman would make the sign of the cross on her forehead.
German and Austrians placed a candle in the window during Christmas as a sign to Mary and Joseph there was room in their home.
Do you have any other suggestions from different ethnic areas as to other Catholic practices?