The best avocados to use are those that gently yield to pressure and are free from dark blotches inside the fruit.
** Depending on how large the avocado is and how thick you want your shake.

Scoop the avocado flesh into a blender. Add the ice cubes, condensed milk, the least amount of non-fat milk; puree until completely smooth. Taste and add additional milk if a thinner consistency is desired. NOTE: I like to use the maximum amount of milk.