Diagnosis: Die Deterioration

I came across this quarter today, thought it would make a great teaching tool.  This is a textbook example of Die Deterioration.  See the write up on Error-ref.com. 
Here's a closeup of Liberty.

Over the life of the die, metal flows into and out of the voids in the die.  It looks like doubling and is often misdiagnosed as a doubled die. 

Same quarter, another shot.
Here you see the metal flow lines moving into the devices.  The nape of the neck and tops of the letters are deformed by the metal wearing down the die.

Same coin, In God We Trust.
Here, the D appears doubled. All by itself it might seem like a keeper. Taken with the rest of the photos the issue becomes clear.  The metal flow lines are outward from the center in all these photos.

A holistic approach will help diagnose some of the issues you encounter. Examine the whole coin. When showing a coin to someone online, always offer full shots of the whole coin, front and back.  There is information that an experienced eye can glean that you may not know to mention.