i use my 4th finger to do a pinch. i guess you cant really call it a pinch now but does the same thing. how i do it is to hold th pick how i would normally then i touch the string with my 4th finger seems easier for me, but dont know anyone else who does it this way. also try an find the "sweet spot" cos only certain places on the string will give you that sound as with normal harmonics only working at certain frets ie 12th. so go up and down the string huntin down the sweet spots. have fun!