"If you're invested in a rental property, you do have to work on it once a month or once a quarter to make sure everything's flowing smoothly. Or, if you have dividend incomes, you [may] occasionally have to check the funds to see which ones are paying out the best dividends, or read the statements, and make sure you're in tune with it," Osborn adds. "If you have income from a business, you want to at least look at the tax returns once a year and make sure the books are balanced — even if you're not operating the business and you're just a partner."