It is not necessary to use a blender to make a milkshake; it can be made with a large spoon and a mixing bowl. Leaving the ice cream out on a counter for about 30 minutes prior to making the milkshake softens it and makes it easier to work with.
Using 4 cups ice cream to 2 cups milk makes a milkshake of average consistency and serves four people, but this formula can be altered to suit thickness preferences and serving needs. Optional flavorings include sugar, vanilla extract and cocoa powder. All ingredients should be stirred together until completely mixed.