1. put the frozen berries, 6 tablespoons of greek yogurt and a small glass of apple juice (and 4 - 5 ice cubes if you are using fresh fruit) in the blender and pulse.
2. When this mixture has blended slightly put on a high setting until smooth (You will probably have to keep pushing the larger berries down to the bottom of the blender as the blades are at the bottom).
3. Add the sweetener (or icing sugar/honey) to taste and blend in.
*Tip* you may not have to add extra sweetener if the apple juice you have used has added sugar, make sure to taste the smootie before adding extra sweetness.
4. Serve in a glass and enjoy!