The Origins of Common Good Luck Traditions
The saying refers to what a bride should wear or carry on her big day. The origin of "old" stems from either an old garter given to her by a happily married woman to convey happiness or symbolize the continuity of loyalty from the couple's friends. Something new is a symbol of luck and health in the future marriage. The borrowed item is supposed to give the bride's friends and family an opportunity to bestow upon her a good luck charm which must be returned for the luck to hold. Something blue originates from ancient Israel, when a blue ribbon was worn by the bride to symbolize her fidelity. The penny or any other coin ensures wealth for the future couple.
The veil is supposed to fend off evil spirits and the richly clad bridesmaids are there to surround the bride and to distract and confuse envious spirits or the devil from harming her. Today, practicality and professional commitments tend to determine the choice of the wedding day, but once it was of great importance which day of the week was chosen. Here is another rhyme:
Monday for wealth, Tuesday for health, Wednesday best of all, Thursday for losses, Friday for crosses, Saturday for no luck at all. Given that today statistically Saturdays are the busiest days for weddings, it either proves that there is not much truth in the saying or it doesn't bode too well for the institution of marriage.
A lot of superstitions surround travel. Never travel on Friday the 13th. 13 generally is thought to be an unlucky number, which is why many hotels don't have a 13th floor and many airlines skip a row 13. The number 13 allegedly stems from the Last Supper with the traitor Judas making the 13th participant. Friday the 13th as a bad luck day is sometimes thought to originate from Noah, and the flood beginning on a Friday, but it's open to debate, as for instance in Spain, the unlucky day is Tuesday the 13th.
Cleaning house before setting off on a trip is considered good luck, as is, in Russia, sitting on ones' luggage. Carrying a good luck coin or a four leaf clover charm ensure a safe trip. There is no apparent reason why a four leaf clover should be the harbinger of good luck, other than that it's very rare. In Christian tradition, it's also believed that the three leaves symbolize the Holy Trinity, whereas the fourth stands for God's grace and protection.
Wealth and General Good Luck
A German belief is that carrying a fish scale in your wallet will ensure that you never run out of money. A horseshoe over the door will bring luck and wealth to the owner of the dwelling, but it needs to be open on top to catch the luck. Upside down, the good luck will run out. Touching wood is supposed to bring good luck. The tradition is based on a pagan belief that woods and trees were the seats of benevolent spirits which were invoked by knocking. Other signs and rituals of pending luck and wealth are crossing ones' fingers, spitting three times and an itching palm.