Put the vanilla, sugar, milk, and chocolate chips (optional) into the smaller bag.
Seal the bag and shake the bag to mix up the ingredients.
Add the ice and the salt into the larger bag.
Make sure the smaller bag is sealed tight and put it in the larger bag.
Shake constantly for 5-8 minutes or until the mixture inside the small bag is firm.
Put your ice cream in a bowl if desired... grab a spoon and dig in :)