Plus, the one mistake to avoid.Credit: Allrecipes / AdobeJust as we might differ in our beliefs about the qualities of the “perfect” chocolate chip cookie, many diners have different opinions about what makes a meatball marvelous. But we can all agree that a dense, dry meatball is a recipe for disappointment.“The ideal meatball is well-seasoned, light, fluffy, and super tender. It should almost melt in your mouth,” explains cookbook author MacKe…