Make a very small bag from rabbit fur, or some expensive cloth, embroidering sigils of wealth on it with whatever skill you have, using appropriate materials. Fill the bag with a special coin (like a silver dollar or a gold doubloon), then drop in an appropriate amount of your sweat and blood. Hang the bag from a string, and consult it as a pendulum when you require sight in a financial blind spot, such as an unknown factor in an investment.