After looking on the web for add'l resources for thoracic problems, I found a cool resource that maps a given pain to the appropriate stretch. The instructive advice for "tight traps" is
here.
And the reference chart that shows the appropriate stretches are
here.
An excerpt:
....Computer users and others who use their arms for extended periods of time will recognize the burning pain between the shoulder blades.
Referred pain from the Trapezius can be found in such a wide variety of locations, that it commonly leads to misdiagnosis, including shoulder bursitis, headaches, disc compression, or a �pinched nerve.� Using the Pressure Pointer may help alleviate your symptoms....
Useful stuff!