Buy three safes. One for "bulk product," one for "inventoried, ready-for-sale product," and one for cash. "If you put your cash in with the cannabis, it will end up smelling like cannabis, and when you go down to the bank, I guarantee you're going to have a talk with the manager of that bank."

Get an ATM — and be prepared to stock it with cash yourself. Credit card companies may not want to do business with you. Same goes for the companies that run ATMs in small businesses. "The companies that traditionally maintain ATMs will not stock your cash," Davis says. "Why? Because it's possible that the federal government will come, break down the door and take that cash."