Christmas stockings ...

While there are no written records of the origin of the Christmas Stocking, there are popular legends that attempt to tell the history of this Christmas tradition. One such legend has several variations, but the following is a good example:

Very long ago, there lived a poor man and his three very beautiful daughters. He had no money to get his daughters married, and he was worried what would happen to them after his death. He thought they would become prostitutes.  Saint Nicholas was passing through when he heard the villagers talking about the girls. St. Nicholas wanted to help, but knew that the old man wouldn't accept charity. He decided to help in secret. After dark he threw three bags of gold through an open window, one landed in a stocking. When the girls and their father woke up the next morning they found the bags of gold and were, of course, overjoyed. The girls were able to get married and live happily ever after. Other versions of the story say that Saint Nicholas threw the 3 bags of gold directly into the stockings which were hung by the fireplace to dry.

This led to the custom of children hanging stockings or putting out shoes, eagerly awaiting gifts from Saint Nicholas. Sometimes the story is told with gold balls instead of bags of gold. That is why three gold balls, sometimes represented as oranges, are one of the symbols for St. Nicholas. And so, St. Nicholas is a gift-giver. This is also the origin of 3 gold balls being used as a symbol for pawnbrokers.
A tradition that began in a European country originally, children simply used one of their everyday socks, but eventually special Christmas stockings were created for this purpose. The Christmas stocking custom is derived from the Germanic/Scandinavian figure Odin. According to Phyllis Siefker, children would place their boots, filled with carrots, straw and even sugar, near the chimney for Odin's flying horse, Sleipnir, to eat. Odin would reward those children for their kindness by replacing Sleipnir's food with gifts or candy. This practice survived in Germany, Belgium and the Netherlands  after the adoption of Christianity and became associated with Saint Nicholas as a result of the process of Christianization.