Sal is correct about soaking the breadcrumbs in some milk. It definitely makes a more tender meatball. Something in milk inhibits the protein bonding of the meat. I forget the whole deal but it really works. If you’re making Italian meatballs I recommend Basil & a bit of Oregano. I usually use basil 3 to one with Oregano. I don’t put much salt in my cooking at all anyway.