What determined a person's destination in Aztec cosmology was not conduct. It was the manner of death. Warriors who fell in battle and captives sacrificed accompanied the sun; women who died in childbirth were counted with them; those taken by water or lightning went to Tlalocan; and everyone else, which is nearly everyone, went to Mictlan. A good life did not qualify a person and a bad one did not disqualify them.
The journey took four years and passed nine levels, each with an obstacle: clashing mountains, a hill of obsidian blades, a wind carrying knives, a place where hearts are eaten. Grave goods were provisions for it. At the end the dead arrived before Mictlantecuhtli and Mictecacihuatl and were finished, which is not a reward and not a punishment.
The first obstacle is a wide river, and the dead needed a dog to carry them over. Dogs were bred, kept and buried for the purpose, and dog burials associated with human ones are found archaeologically across the region. The Xoloitzcuintli, which is still a recognised breed, carries the name of the god Xolotl. It is a rare case where a doctrine about the afterlife produced an animal that is still alive.
The annual observances now known as the Day of the Dead descend in part from this material, by way of a long and much argued negotiation with the Catholic calendar. How much of the modern festival is pre-Columbian and how much is colonial and later is genuinely disputed among historians, and confident statements in either direction should be treated with caution.