Acorns
In Scandinavia folklore, the acorn, fruit of the oak tree, will bring good fortune to the bearer. An acorn placed on a windowsill of the house will protect it from lightning.
Horseshoe
The horseshoe is supposed to bring good fortune when hung on the wall of a home or doorway. The U shape will hold good luck inside forever.
Rainbow
If you want to get rich, follow a rainbow, andof you're lucky you'll find a pot full of gold at the end. At least, that's what could happen according in folk belief.