Think about picking up a worm. Think about how your hand cups and gently holds, creating a space just for that worm. The cupped hand is a safe place for the worm. Your fingertips still feel the sensation of digging in the cold dirt and your forefinger and thumb remember gently picking up that worm to place it in your other palm, crossing your midline while those fingers curl towards the palm. You feel the worm move, it tickles.
All these little sensations, the manipulation of fingers in soil to pick up and hold the worm, these will teach you to write!