Placing keys on a table is considered unlucky. (Sweden)
3
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
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
It is bad luck to put new shoes on a bed (or a table) (comes from the tradition of dressing a corpse in new clothes and shoes and laying them out so everyone can give their respects) - (UK)
57
Some motorcycle enthusiasts hang a biker's bell from a portion of their bike to protect themselves from evil road spirits.
64
It's bad luck to leave a house through a different door than the one used to come into it.
143
According to an age old custom, carrying a dead shrew in your pocket wards off rheumatism!
24
If you catch a falling leaf on the first day of autumn you will not catch a cold all winter.
394