At every shrine and temple you visit in Japan, there is a booth selling Omamori or lucky charm amulet things. I never know what is for what so I haven't bought them. I did recieve a beautiful gift of one when I found out I had cancer last fall (Thank you Sano San!)
They are especially popular during the New Year Holidays and during test taking times, and with both Shinto believers and Buddhists. They are made with a fancy silky fabric and have little printed prayers inside, but you aren't supposed to open it or you will release the blessing and say good-bye to the good luck. (How does anyone know there is a prayer inside if you can't look?) The good luck is said to last about a year, then you need to get a new one. There are special Omamori for every different category you can think of - success, money, travel, ward off evil, learning and education, love, traffic safety, to name a few.
I'm not superstitious, nor am I Shinto or Buddhist, but somehow I believe in this omamori. I have had some medical challenges, but I haven't had any horrible side effects from the chemotherapy and my broken arm is healing much faster than I imagined it would. I think I am very lucky.