If it's just my wife and I on the boat we know what needs to be done in a docking situation so well that regardless of who's driving and who's the "deckhand" we rarely have to actually say anything to each other as we're executing the maneuver aside from the deckhand letting the driver know when such-and-such a line is attached. Or in the case of pivoting backwards out of a tight spot while being blown onto the dock, the driver tells the person with the bow breast line when to release and haul it in as the boat backs off.
And since we always drive from the lower helm, communication is easy since both of us are only a few feet apart.
When we have guests and we feel that they are competent to help in a challenging docking situation (which is the only kind of guest we allow on the boat anyway
) the rule is that whichever one of us (me or my wife) is being the "deckhand" he or she has charge over the helpers. The driver just drives and communicates only with the deckhand.
We have found that this eliminates conflicting orders and this confusion on the part of our "assistants."
Prior to every docking or departure other than our home slip my wife and I discuss the situation and what our plan of approach (or departure) is prior to executing the actual maneuver. If there are options or "what happens if?" questions we figure them out beforehand.
If we have guests, whoever the deckhand is tells each guest exactly what their task is, why they're doing it, and what their actions area supposed to result in.
So far in all the years we've been doing this, it's worked great.