Another old German formula:
Buy a mirror for the offered price and write on it S. Solam, S. Tattler, S. Echogarter Gemator. Dig a hole at a crossroads, at an odd-numbered hour, and take it out. Do not look into it at first, but let a dog or cat look into it.
It’s unstated, but apparently something bad happens to the dog or cat. As such, it is not approved by my fiancee, so use at your own risk.