I THINK I KNOW WAT YOU MEAN.
YOU TALK ABOUT PINCH HARMONIC RIGHT???
JUST PLAY THE STRING AS USUAL BUT AT THE EXACT SAME TIME
TRY TO TOUCH IT (VERY VERY SLIGHTLY) WITH THE SIDE OF YOU THUMB AND REMOVE YOUR THUMB AT THE EXACT MOMENT YOU TOUCHED IT TO LET IT SOUND OR ELSE YOU'LL MUFFLED YOUR STRING AND YOU WONT DO IT RIGHT. ITS VERY HARD TO EXPLAIN
LIKE THIS BUT KEEP TRYING AND MAYBE IN 4 OR 5 YEARS YOU'LL GET IT.... SERIOUSLY ITS NOT THAT HARD.

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