In my opinion, the best way to teach docking is to teach two prerequisites first:
- Slow sailing (then...)
Once the student can stall out next to a man over board. I'm comfortable giving them full decision making and control over the more risky situation (for the boat) of letting them dock.
When first learning docking, they basically just start off with doing a man-over-board drill.... except they're stalling out in front of the dock.
I always (at first) have them aim for the downwind end-corner of the dock... because its got an easy abort route... and if they are coming too hot I can just have them do a slight turn and race past without hitting the dock.
As they improve, let them practice shooting for other parts of the dock. Just like in billiards, make them call their "shot". It will help them be more precise in bridging the gap between what they intend to do and what they actually do.