Bad Luck
Along with the good there is always the bad. There are about as many if not more bad luck stories than good luck stories. Things you should not do, for consequences will follow.
If you spill salt throw it over your left shoulder or bad luck will come. This superstition comes from the past. A time when to waste was to want, a time when salt was very expensive and quite valued as a commodity. Salt was also considered the purest of substances. If one was to spill salt by mistake, he/she must throw the salt over the left shoulder. This was to temporarily blind the devil that sits there, and prevent him from bringing misfortune.
One should not whistle on a ship, it incurs the wrath of the ocean and bad luck will follow. In the past, sea travel was very dangerous. Sailors were very superstitious to prevent their demise at the hands of the ocean. This one I believe was used by fishermen also, maybe still!
To walk under a ladder is bad luck. This comes from a very real danger in when people were hanged publicly. Often ladders were placed on the gallows so that the body could be cut down and removed. If one was to walk beneath the ladder as this was being done, the body might fall on that person's head. Not a pleasant thing if you ask me! That is where this superstition was born, for death and spirits were greatly feared.
Don't wear grey mittens on a fishing boat.
If you put three lamps on the table there will be a death in the family.
A knife stuck in the butter is bad luck.
It is bad luck to look at the new moon through the window.
If you break a sewing needle while sewing your trouseau, you will die within a year.
Don't...
Set a hem in the dark of the moon.
Kill a pig in the dark of the moon.
Plant corn in the dark of the moon.