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
Two people breaking a wishbone is said to lead to good luck for the person with the larger piece.
225
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
According to an age old custom, carrying a dead shrew in your pocket wards off rheumatism!
24
Some motorcycle enthusiasts hang a biker's bell from a portion of their bike to protect themselves from evil road spirits.
64
Placing a hat on the bed is, apparently, bad luck. (South Carolina)
9
It's bad luck to leave a house through a different door than the one used to come into it.
143
Placing keys on a table is considered unlucky. (Sweden)
3