Continue feeding the sausage mixture into the casing, using your free hand to regulate how tightly the sausage is packed; make sure not to overstuff the casing. When the casing is nearly stuffed, tie off the other end.
Lay the sausage on a damp surface. Starting at one end, pinch off the first link by pinching your fingers into the sausage to separate the filling; 4 inches is a good average length. Then, roll the link toward you 3 to 5 times, creating a twist in the casing. Move down to form the next link, rolling 3 to 5 times in the opposite direction (this prevents unraveling).