I like the idea of getting one line through the eye of the pennant of the mooring ball and back to the cleat, preferably on the starboard side as stated. Now the fellow at the helm is prohibited from screwing-up the whole operation. If he has done a good job (probably not) at bringing the boat to a stop with the pennant centered, then you can easily retrieve the eye by pulling on the secured line, threading the second line (port side) and back to the cleat. You can then tell him to cut the engines and go get a beer while you are adjusting both lines for a secure overnight stay. Be sure to compliment him for the excellent job of operating the boat.