Pizzicato is an effect common to all stringed instruments, i.e. the violin, where the term means to pluck the string as opposed to the normal bowing. In guitar playing, pizzicato means to dampen the sound of a note or chord by:
Placing the palm of the right hand (nearest the little finger) in the groove behind the bridge saddle (see photo A).
Rolling the hand over to allow the fleshy side of p to strike ^,and at the same time allowing the palm to lay over the bridge saddle and lightly on the strings (see photo B).
The combination of using the flesh of p to pluck the string and the muting caused by the palm resting on the strings, produces the pizzicato effect. Pizzicato is most commonly used in single note, scale-like passages and it is often necessary, when playing on the treble strings, to move the hand across to accommodate p (see photo C).
Pizz, hand position. as in photo B.
Pizz, hand position. as in photo C.