Hang a horseshoe on your door with the open end up for good luck.
The horseshoe is considered to be a good luck charm in a wide range of cultures. Belief in its magical powers traces back to the Greeks, who thought the element iron had the ability ward off evil. Not only were horseshoes wrought of iron, but they also took the shape of the crescent moon, which fourth century Greeks considered to be a symbol of fertility and good fortune.
The belief in the talismanic powers of horseshoes passed from the Greeks to the Romans, and from them to the Christians. In the British Isles in the Middle Ages, when fear of witchcraft was rampant, people attached horseshoes open-end-up to the sides of their houses and doors. People thought witches feared horses, and would shy away from any reminders of them.