Hello, Howard.
The techniques involved in all of the above take practice and dedication to make them look presentable. Any nitwit can slather on stains and glazes in different amounts to show dimension, but true accenting is different.
I would start with any books from Dresdner
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Flexner
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Jewitt
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get the ball rolling. There are other good books out there as well, and all of those guys have more than one out.
As far as shading and toning go, you should look into the great stuff some of the luthiers are doing. A three toned sunburst guitar is a thing of beauty, and some of those guys are real masters at designing and creating those finishes.
The basics of the guitar wood coloration (for the purists, I did not say finishing) is no different than any other wood that you shade, tone and stain, etc.
Robert