Place your sandwich bags inside of cups to keep them open while you add ingredients.
Add a half cup of milk into each bag.
Pour in a 1/2 teaspoon of vanilla.
Add 1 1/2 tablepsoons of sugar to your ice cream mix.
Close up the bags, and secure the opening with masking tape.
Fill a gallon size bag about 3/4 of the way full with ice. Add in six tablespoons of ice cream salt.
Place your bag of ingredients into the gallon size bag of ice. Close and secure the opening of this bag, too.
Shake the bag for 5-10 minutes, or until the ice cream reaches the consistency of a thick milkshake.
Add toppings, if desired, and enjoy!