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
An acorn should be carried to bring luck and ensure a long life.
115
If you catch a falling leaf on the first day of autumn you will not catch a cold all winter.
394
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
Placing keys on a table is considered unlucky. (Sweden)
3
Collect seven or nine different flowers on midsummer eve and place them under your pillow and it is said that you will dream of your future spouse. (Sweden)
463
Once a wedding ring has been placed on the finger, it is considered bad luck to remove it.
117
In Asia, the digit 4 never appears in any Nokia handset model number, because 4 is considered unlucky in many parts of Southeast/East Asia.
78