The secret to making the perfect matzo ball is to handle it a little as possible. I learned this from my grandmother. I was probably six or seven, and I remember standing in the kitchen during Passover, watching the food prep take place. My grandmother was on matzo ball duty and my mom was asking how she always got hers to be "floaters*" and taste so fluffy. My grandmother replied simply, she said the trick is to barely touch them, handling them as little as possible.
*float•er | 'flōtər - a tasty matzo ball that is light and porous, causing it to float at the top of the soup pot, and making it easy to scoop up and serve and delicious to eat, unlike a "sinker" which drops straight to the bottom of the pot because it is too heavy and dense.
