Rinse off the quart-sized bag before serving to remove the salt.
You can add mix-ins, such as sprinkles, cookies, fruit, or candy, when you're finished shaking the bag.
If your ice cream is not thick enough, add more salt to the ice mixture to help it get cold enough.
If the bag is too cold for you to hold when you shake it, wear gloves or cover the bag with a towel.
While rock salt is best, I tested this recipe with kosher salt since most people have that in their kitchen and it worked perfectly. If you use rock salt, you will shake a few minutes less.