How do you visualize the fretboard? Do you think note names, interval
shapes, scale patterns or some combination?
I believe in exploring the neck in every way possible.
I recommend doing position work in second position, single string work up
and back down each string and diagonal work, forward for scales and
inverse (higher frets on lower strings to lower frets on higher strings) for
triad block arpeggios.
Positions can be broken down in to strict lateral positions and floating
positions (typically three notes on each string).
For note names, say it as you play it - use muscle memory to reinforce the
note knowledge.
Breaking down scales and chords intervallically covers both the knowledge
and sound of the intervals, and melodic phrases can be sequenced
through scales and chords.
What are the best guitaristic shapes to use when soloing over a II V I
(both minor and major)?
Explore multiple ways to arpeggiate the chords, keeping around a basic
area of the neck and developing a path for the changes. Then move to
another region of the neck and explore in the same way.
Having multiple fingerings in multiple places allows you to be more
spontaneous in how you travel around the neck as you play.