The wrist should be sent out slightly.
In principle, the thumb should be in the middle of the neck, the direction of the thumb should not be parallel to the fingerboard, and should be between the index and middle fingers. However, the neck of the folk song is narrow, so the fingering of the thumb is not static, and sometimes the thumb can also press the strings. No matter what finger position is used, it should be beneficial to change the handle.
There are many combinations of the index finger, middle finger, ring finger and little finger, but there are some rules that must be adhered to: (1) Each finger should use the fingertips to press the strings. (2) Each finger should press the string at an angle perpendicular to the finger pull as far as possible. (3) The position of pressing the strings should be as close to the fret as possible. (4) The knuckles should be bent, not rigid or bent inward to form a folded finger (fingerplay has the technique of pressing the 4th, 5th, and 6th strings with the index finger and folded fingers).
