Mix yogurt and sweetener in a small bowl and spread evenly into an cube ice cube tray. Freeze yogurt for at least 4 hours, or more.
After the yogurt has frozen, begin making your smoothie packs. Start by placing half of each banana and 1 cup of berries into a ziplock bag, along with four of the frozen yogurt cubes. Seal each bag and place into freezer until ready to use.
To make a smoothie, add 1 cup milk to a blender, followed by the ingredients for one of the smoothie packs. Blend until smooth. Enjoy!