First, the steps are:

1. fingering:

Thumb or finger: strings are usually made with the fingertips of thumb or finger. When the thumb is used to strike the strings, it has more power and control.

Finger position: put your finger in the right position, usually between the bridge and the speaker. The closer to the speaker, the brighter the sound.

2. Increase the rhythm:

Rhythm: Understand the position of rhythm and bounce. Practice more and gradually form your own sense of rhythm and habit of playing strings.

3. Wrist control:

Wrist movement: control the strength and flexibility of the wrist to produce different timbre and rhythm.

Practice adjustment: adjust the strength and position of the wrist in practice to find the right way to hit the ball.

Second, skills:

1. Different timbres:

Percussion position: Percussion strings produce different timbres and effects at different positions. The sound produced near the bridge is sharper and brighter, and the sound produced near the speaker is softer.

2. Rhythm control:

Rhythm change: The rhythm change and style can be controlled by changing the speed, strength and frequency of striking strings.

3. Practice and skills:

Continuous practice: it takes a long time to practice and hone, try and explore constantly, and gradually improve the skill and level of bullet hitting.

Third, matters needing attention:

Hand protection: Capturing requires a certain amount of hand strength, and attention should be paid to the protection of hand muscles to avoid injury caused by excessive force.

Keep practicing: This skill requires persistence and constant practice. Don't be discouraged, try and practice more.

Playing the string while playing is a skill that requires constant practice and patience. Through constant practice and exploration, combined with your own musical feeling and personal style, you can gradually master and improve the application level of this skill.