A good meal replacement smoothie rarely happens by accident. Those runny chocolate milk wannabe mixes won't tide me over until lunch. I prefer a thick milkshake style meal that I can sip slowly.  To save time, I pre-mix the dry ingredients and store them in pint size mason jars. If you need a quick way to sneak a few green things into your family's smoothies, this is the fastest, most subtle way to do it.