I’m a huge fan of Green Smoothies and eat them probably 14/15 days for breakfast. I ran across this excellent article the other day about 6 foods to avoid adding to smoothies and I wholeheartedly agree with its advice.
The article mentions that dried greens are not terrible, but fresh ones are better. I usually depend on my organic box for greens, but some weeks are a little light and I run out towards the end of the week. If it is, this is my go-to dried green powder, which I order on Iherb: Greens Plus Organic Superfood.