In the pint sized ziploc bag, mix the sugar, half and half, and vanilla. Seal bag tightly.
Now take the gallon-sized Ziploc bag and fill it up halfway with ice and pour the salt over the ice. Now place the cream filled bag into the ice filled bag and seal.
Shake for 5 to 8 minutes until the ice cream is very firm and hardens.
Open the gallon-sized bag and check to see if the ice cream is hard, if not keep shaking. Once the ice cream is finished, quickly run the closed pint-sized baggie under cold water to quickly clean the salt off the baggie.