Once a wedding ring has been placed on the finger, it is considered bad luck to remove it.
117
Two people breaking a wishbone is said to lead to good luck for the person with the larger piece.
225
Before traveling a person should, apparently, sit on their luggage. (Russian)
117
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
An acorn should be carried to bring luck and ensure a long life.
115
It's bad luck to leave a house through a different door than the one used to come into it.
143
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
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