I'm a big fan of the "throw everything in the blender" smoothie recipes -- when the girls were smaller, we did yogurt, milk, and some fruit (bananas, strawberries) -- so that largely wouldn't work for you. With ds, I do juice, yogurt (do you have a good yogurt sub?), greens (spinach, kale, etc), and frozen fruit (strawberries, berry mixes, mango, etc). Maybe leave the greens out at first -- spinach is the least distinctive taste out of all the greens if you wanted to try one.