yeah all the above and the E.Q idea on
I was thinkin maybe when you tryin to find this elusive harmonic sound one could consider where the right hand is digging (pinching into the string.
I.E)are you above the bridge pick up?,..neck pick up?
somewhere in between or even on the fretboard.....anywhere.)
that effects the attack and tonality alot too.
also a way of the butt of your right hand brushes the same string ever so slieghtly as you dig in or pinch for the harmonic is a great way to vary the sound too.