An acorn at the window will keep lightning out
93
If one walks underneath an open ladder it is said to bring bad luck. Sometimes it is said that this can be undone by immediately walking backwards back underneath the ladder.
105
If you catch a falling leaf on the first day of autumn you will not catch a cold all winter.
394
There are numerous sailors' superstitions, such as: it is considered bad luck for a ship to set sail on a Friday, to bring anything blue aboard, to stick a knife into the deck, to leave a hatch cover upside-down, to say "pig", or to eat walnuts aboard.
70
When you speak of bad luck, it is said that one should always knock on wood. Also knocking when speaking of good luck apparently helps with having good luck. This is an old Celtic tradition related to belief of wood spirits.
208
Before traveling a person should, apparently, sit on their luggage. (Russian)
117
The superstitious symbolism of a black cat crossing one's path is dependent upon culture: some cultures consider this a sign of impending bad luck, while some cultures consider this a sign of impending good luck.
75
A single magpie is considered a sign of bad luck. A Guide to the Scientific Knowledge of Things Familiar recites an old proverb concerning the incidence of bad weather when magpies forage alone and a possible scientific explanation for this.
49