Placing a hat on the bed is, apparently, bad luck. (South Carolina)
9
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
Breaking a mirror is said to bring bad luck for 7 years. To "undo" this, take the shards of glass and bury them underneath the moonlight. In ancient times, the mirror was said to be a window to the viewer's soul. If that mirror were to break, it would
123
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
Once a wedding ring has been placed on the finger, it is considered bad luck to remove it.
117
Before traveling a person should, apparently, sit on their luggage. (Russian)
117
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
Placing keys on a table is considered unlucky. (Sweden)
3