In a gallon size heavy duty zip loc back place:
2 C Ice
2 tbsp Table salt
In a quart sized zip loc bag place:
1 C Milk
1 tbps Sugar
1 tsp Vanilla
Chocolate syrup (optional)
Seal the smaller bag tight and place in the large bag with ice. Seal the larger bag and make sure it is resting on top of the smaller bag. Now shake... shake.. shake. This will take approximately 10 minutes. On a hot summer day it might take longer!