Meatball help!?

My meat are not the consistency I desire. Mine are too dense, to "rubbery." I've had people say use more egg, less egg, more breadcrumbs, less breadcrumbs, hi fat meat, low fat meat, onions for moisture, no onions-too much moisture. What is the real deal? The taste of mine is great, it's really just the texture I need to work with. Any ideas?