Watch the Minor Sixth online guitar lesson by Kai Eckhardt from Atomic Bass: Reactive Intervals
The variation drill lines out the minor sixth interval in so many parallel ways always straying true to its sound. Notice how the major third (the inversion) is used to keep the intervals lining up within the two octave range, never using any notes that don't belong. This way, by playing the drill, you subconsciously become familiar with the pure sound of this unique tonality. And later on you will recognize it instantly wherever it occurs. Tonal centers for this one are G, G#, and A.