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
An acorn should be carried to bring luck and ensure a long life.
115
Placing keys on a table is considered unlucky. (Sweden)
3
At times, a horseshoe may be found above doorways. When positioned like a regular 'U' it supposedly collects luck. However, when it is positioned like an upside-down 'U' the luck supposedly drains.
78
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
Pirates believed that piercing the ears with such precious metals as silver and gold improved one's eyesight.
132
Two people breaking a wishbone is said to lead to good luck for the person with the larger piece.
225