1. Death tattoos: Santa Muerte - origins and significations
Most of the Santa Muerte tattoos, especially those which are made by unskilled "artists" or those made under improper conditions (like prisons) are usually cheap depictions of the Grim Reaper: a skeleton dressed in a long hooded cloak, carrying a scythe.
More original images actually portray the feminine aspect of the character, and a look that often resembles a skeleton version of the Virgin of Guadalupe (the patron saint of Mexico, Patroness of the Americas, Empress of Latin America, and Protectress of Unborn Children).
If she's not portrayed as a skeleton version of the Virgin of Guadalupe, the Holy Death (Santa Muerte) is very often portrayed as a dead young woman. In this case, one can identify a Santa Muerte tattoo by the presence of certain elements: an aura around the head or around the entire body, the presence of the human skulls at the bottom of the tattoo, the praying hands, the presence of the flowers (Santa Muerte worshipers are supposed to offer her flowers along with food, tobacco, money, prayers, and, of course, their faith).
Usually, Santa Muerte is depicted wearing either a long robe or (less commonly) a long dress, covered from head to feet with only the face and hands showing. The color of the dress can be white, yellow, blue, black or red (in exchange for a peaceful death, the Aztecs used to offer blood to the king and the queen of the Mictlan - Mictlantecahtli and Mictecacihuatl; because blood offerings were considered of utmost importance the color red became intimately associated with the king and the queen of the Land of the Dead). However, due to the fact that coloured tattoos are quite expensive, very often the entire tattoo is made only with regular blue or black tattoo ink.