mandoleer - they often are landed with their patronage by the way of their martyrium i. e. how they were put to death:

- Apollonia: After her teeth were broken with pincers, she was given the choice of renouncing Christ or being burned alive; she lept onto the fire herself. Patronage: dentists, toothache

- Florian: a stone tied to his neck, and dumped into a river. Patronage:
..., against fire, ..., barrel-makers, brewers, ..., coopers, drowning, fire prevention, firefighters, [against] loods, ... [He was originally a patron of things or persons connected with water; since water was the main medium for extinguishing fires, he became patron of firefighters, too]

- Nicholas of Myra: Generous to the poor, and special protector of the innocent and wronged. Many stories grew up around him prior to his becoming Santa Claus. Some examples:
    * Upon hearing that a local man had fallen on such hard times that he was planning to sell his daughters into prostitution, Nicholas went by night to the house and threw three bags of gold in through the window, saving the girls from an evil life. These three bags, gold generously given in time of trouble, became the three golden balls that indicate a pawn broker's shop.
    * He raised to life three young boys who had been murdered and pickled in a barrel of brine to hide the crime. These stories led to his patronage of children in general, and of barrel-makers besides.
    * Induced some thieves to return their plunder. This explains his protection against theft and robbery, and his patronage of them - he's not helping them steal, but to repent and change. In the past, thieves have been known as Saint Nicholas' clerks or Knights of Saint Nicholas.
    * During a voyage to the Holy Lands, a fierce storm blew up, threatening the ship. He prayed over it, and the storm calmed - hence the patronage of sailors and those like dockworkers who work on the sea.
Patronage: against imprisonment, against robberies, against robbers, apothecaries, bakers, barrel makers, boatmen, boot blacks, boys, brewers, brides, captives, children, coopers, dock workers, druggists, fishermen, Greece, Greek Catholic Church in America, Greek Catholic Union, grooms, judges, lawsuits lost unjustly, longshoremen, Lorraine, maidens, mariners, merchants, murderers, newlyweds, old maids, parish clerks, paupers, pawnbrokers, perfumeries, perfumers, pharmacists, pilgrims, poor people, Portsmouth England, prisoners, Russia, sailors, scholars, schoolchildren, shoe shiners, Sicily, spinsters, students, thieves, travellers, unmarried girls, watermen

- Nicolaus Nepomucenus (not in the Calendar any more): thrown from the bridge of Prague. Patronage: bridges [on many bridges old and new in Bohemia and Germany his statue can be found]

I hope these few examples show how the saints got their patronages.