If you feel like your meatball mixture is too soft and you are having a hard time rolling the meatballs, you can do a couple of things to thicken it. Add about 1/4 to 1/3 cup or panko bread crumbs and mix well. You also need to make sure to keep your hands greased. I like to keep a shallow dish with a tablespoon or so of oil in it to dip my hands after rolling every 2-3 meatballs.