It's bad luck to leave a house through a different door than the one used to come into it.
143
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
Before traveling a person should, apparently, sit on their luggage. (Russian)
117
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
Placing keys on a table is considered unlucky. (Sweden)
3
Once a wedding ring has been placed on the finger, it is considered bad luck to remove it.
117
An acorn should be carried to bring luck and ensure a long life.
115
An acorn at the window will keep lightning out
93