Q&A for How to Jitter Click

Try not to tense your whole arm up to your shoulder, just tense your forearm/elbow. It takes practice, if you do it for a long time and get used to it, it will not hurt your hand.

Hold the sides of your mouse with your thumb and pinky and find a grip on the left mouse button that's right for you (mine is my index finger and my middle finger, or just the middle finger). Vibrate and it will be easier once you have found your grip.

You might like to try one of these: the Razer Deathadder, Razer Viper, or Logitech G502. Go with the Razer Deathadder if you have larger hands, go with the Viper if you have smaller hands, go with the G502 if you are an FPS try-hard.

Jittering on an office mouse might be okay for you, but for some other people jittering on a gaming mouse is easier because they have lighter clicks, which allows you to not tense your arm that hard and not hurt your arm.

Focus on doing smaller vibrations; try not to shake your arm too much. Try vibrating less of your arm, instead of up to your elbow. Ideally, you want to only have to vibrate down to a little below your wrist, instead of the whole arm.