The viola is a many splendored thing. I love being a violist; playing, listening, even practicing it most of the time. It is difficult, though, to explain what it is I do in the practice room to people who haven't studied an instrument.
Here is my bow. Here is my bow on drugs. Actually, here it is in two places on the string- one will generally make a stronger sound more easily, the other can make a lightly singing sound. They aren't very far apart.
The left hand requires even finer control. In the first pic, I'm playing an f# high up on my g-string. G-string viola jokes just never ever get old, do they? In the second pic, I'm playing an entirely different note, G. In between F# and G there are 1,209,543,875 possible shades of pitch. Most people can hear at least two distinct "quarter tones"- in the music of India there are some players who regularly perform tunes relying on four or more. InBETWEENthe keys of the piano. Little, yet significant.
I spend my time practicing these tiny motions, and some bigger ones. I record myself and listen back daily because all of these minutiea exist to create a specific sound, and that's all that really matters. Then there's musicality and taste- the inflections that make music beautiful and Kenny G a pawn of satan. Let's just not mention Celine Dion.
When I've worked on a tricky passage until I can play it, I then repeat it so I forget it was ever difficult.
I'm sure there are correlations to be drawn between accomplishments in life and in the practice room, but I think most would be lies. Practicing the viola is a strange, specific skill. Like embalming, perhaps, or post-modern thought.