The next surprise is that he has large hands. I read on with interest on several points the writer makes. Let your arms hang at your side. Notice how your hands naturally cup. Notice how you normally grab a mouse.
Most people hold a mouse using their thumb and finger tips.
Your hand now encompasses the mouse. Your finger tips are resting on the table top. Put the cable of the mouse between your forefinger and middle finger. This keeps the mouse in the right position in your hand. Think of your forefinger as the pointer on the screen.