The recipe I use is as follows:
Blend 2 cups frozen fruit (any kind), 1/4 cup sugar till it is the texture of snowy, then while the blender is on pour in about 1/3 cup milk or soy milk. Blend till creamy adding more liquid if needed. You can eat it right away or freeze it for later.
I make it often with fat free original soy milk and it is delicious. Hope it works for you. :D