Principles Vs. Techniques - Value

  I've been having some great insights recently.  I think it's been a result of being more withdrawn and quietly working on myself.  I've also been reading a lot recently which has helped me a lot of realizations.
  What I wanted to talk about mainly was an idea that I've always loved, which is the idea that there are overarching principles that can apply to all disciplines.  In this case one of the main principles in creating a work of art is "value".
 Most people think of value monetarily, but value in a work of art means the lightness and darkness of a color.  So if you looked at a gray scale photo of the world, how dark or how light would the colors appear?  That's what value is.  It helps to imagine value as a scale from 0 - 10 such as seen here:

  The power of value is that it makes it possible to quantify the world into a range.  As artists, we only have a certain range to work within.  In the case of drawing and painting, the scale is very specific.  I think of it often like a piano that has a certain range of notes to play.  Of course, within that range there is a seemingly limitless combination of notes.
  So to go deeper, value is a principle that great works of representational art have in common.  But what makes value good or bad?  I'd say the most important part is to have accurate value.  And that means that you can accurately transcribe the darkness or lightness of a tone from your eye to the paper or canvas.  This is a super simple idea, but the application of it can be very difficult.  
  The reason it's difficult is because the world is mostly composed of midtones; midtones are found in the value ranges from 3 to about 7 on a value scale.  Now a 3 and a 7 look entirely different, but a 3 compared to a 4 and then a 4 compared to a 5 and so on gets trickier.  There's a bit of advice that can help from John Singer Sargent which he received from his teacher, Carolus Duran.  He says that the secret of art is in the half tones and to search for the half tones.  The idea is to find midtones and then find the darks and the lights, working outwards from the middle.  A good painting is mostly midtones, with touches of dark and light on top.
   A lot of my own time was spent pursuing techniques; this happened as a beginner before I was open to learning principles.  One example of techniques is how materials affect your painting.  So you can learn about how poppy seed oil dries slower than linseed oil, so poppy seed oil works well for alla prima painting in order to prolong the drying time.  
  Another way of thinking about this is that techniques are like tools in a toolbox.  It's important to know what a hammer does and what a saw does and how to properly use them, but the principle is like what you're trying to build with those tools.  Techniques and principles are often intertwined together and help each other.  
 Techniques are important, especially for a beginner, but it's important to not get hung up on them and to allow them to facilitate your true creation.  This mindset also lets you have the freedom to create your own techniques and just to have fun with the whole process.  And that's the most important part!