This is why I like the Periscope probe so much.
One of the many advantages of the Periscope probe - too bad it's not currently being manufactured - is that after pinpointing in general - a few quick piercings of the ground with the probe and you can confirm the item is present where you think you've pinpointed it and can literally touch it with the probe end before you ever even stick your digger into the ground.
So you confirm location, depth, size and to some extent can verify metal content of target.
If your off on the pinpointing - a few more pokes around with the probe and you can find the target pretty quickly and easily - most of the offs end up being from poor initial pinpointing.
No ghost holes - because you wouldn't bother to dig if you can't verify with the probe touch - never get a ghost at all this way.
Granted it was an expensive probe but paid for itself in many ways such as time and labor savings in not digging non coin/jewelry targets and in one hole one target recoveries.