When I teach it, on Aow they also have to swing a square, but with an extended first leg, which takes them away from the wreck so they can't see it. The only reference is the featureless sand and the compass. Paranoia and self doubt sets i, but they all eventually get it even after a few attempts - and I get them to use the compass on different dives.
First tip. Make sure you know the direction you're heading away from the drop point, and set that reciprocal bearing at the start of the dive, that way you have a direction to head back too - hopefully you'll have paid some attention to the change of directions you might have made on the dive site - especially to the surrounding area of the anchor line. As you get closer your self doubt will start to wane
On a liveaboard its most likely you'll have a guide with the group anyway, however be familiar with and carry a dsmb, so if all else fails and you get seperated you can launch the dsmb and surface under it, and let the taxi come collect you.
