The correct answer is D) repeat back to the watch officer any rudder commands before executing them. This is the correct answer because it is a key practice for an effective helmsman to repeat back any rudder commands from the watch officer before executing them. This ensures clear communication and helps prevent misunderstandings that could lead to steering errors. Repeating back commands is a standard procedure required by regulations to maintain safe vessel control. The other options are incorrect because: A) applying rudder to move the compass card is not an effective technique, B) keeping the rudder amidships except for course changes is too passive, and C) using excessive rudder is not a good practice and can actually worsen the vessel's course-keeping.