Since prepared smoothie doesn't store as well, I recommend making freezer bags with the smoothie ingredients inside. This way you can quickly make the smoothie in just minutes, and it will still have a fresh flavor and texture. To make the smoothie bag, add the sliced frozen banana, mango, ground flax seed, ginger, and spinach to a freezer-safe bag. You can make as many bags as you'd like to have on hand, then store them in the freezer for up to 3 months. To make the smoothie, dump the contents of the bag into a blender and add the water and orange juice for blending.