Octave playing technique involves playing the same note on two strings separate by one octave. An octave is 12 semitones higher than the root note. You will find in this blog post a new video from the YouTube Channel, containing 10 dominant octave licks with tabs and standard notation overlayed.
Guide tones are the notes in a chord which leads or gives harmonic pull toward the next chord, these are an excellent way to study and absorb the sound of any chord progression.
Guide tones are used to outline chord progressions in an improvisation.
They are most of the time the 3rd and the 7th because this is what determines whether a chord is major, minor, or dominant.