Smoothies can be improvised in many ways. Here was a suggestion I got this week and it was surprisingly good! Use what you have , improvise, improve.
Beet (cooked and peeled)
berries (I used blueberries)
Kale (I used spinach)
cucumber (I used the little i had left)
lime (small squirt, I was a little leery)
coconut milk (almond, cow, etc...will work)
Blend, enjoy the pretty color and taste!