In Victorian Times:

People of "society" were strictly bound and structured by the most elaborate rules and regulations of etiquette. Mourning customs were just one small part of the way they felt they had to conform to the rules or risk scandal by their peers.
Death preoccupied a majority of their time due to the fact that 3 out of every 20 children died before reaching a year old, the life expectancy then was 42 years of age and modern medicine was just in its infancy.
It was possible to "be in mourning" a good part of ones life, losing one relative before the mourning period was over from the one before.
Typical symbols that were used were draped urns, weeping willows, broken columns, and extinguished torches( I have found upside down torches as well.)
Just as people today throw large weddings, in society then, it was the custom to have the most elaborate funerals. Coffins went from plain wooden boxes to being intricately carved and hearse, along with the horses were elaborate and all black, except for infant funerals. For the death of a baby, they used white accents. The normally black ostrich plumes would be white with a white casket and the mourners would wear white gloves. Horses were even dyed black if they weren't black naturally.
Those of means could also hire "professional mourners" called "mutes", who would walk the in the procession from the house to the grave.