Have you seen the smoothie packets in the freezer section at the grocery store? Homemade smoothie packets require minimal prep work, which means it offers the same convenience but is much less expensive.
All you need is yogurt and a bag of frozen berries. You simply put a tablespoon of yogurt into each "cube" of the ice cube tray and freeze them. When they are frozen, put three yogurt cubes into a Ziploc freezer bag with a cup of frozen fruit.
Store them in the freezer, and when you feel like a smoothie, put the contents of one bag in the blender with 1/2 cup of orange juice and blend. This post is linked here: