I always just steamed the veggies until they were a bit soft, and then pureed them in the blender with some yogurt. You get kind of a green juice. Then I add that to just about everything-- sauces, shakes, smoothies, etc. You can even hide it under the cheese in a pizza. If you're using stronger tasting veggies, you can put a tart fruit in there, too, to disguise the taste. When I'm putting kale in a smoothie, I always use strawberries too, because the taste of the strawberries dominates enough that you don't even notice the green stuff.
Our favorite smoothie consists of a banana, strawberries, a heaping spoonful of honey, yogurt, crushed ice, and "green juice." (Usually kale or spinach, since we raise those ourselves and always have too much, but any leafy vegetables or root vegetables will work.)
I wouldn't use protein powders. We avoid overly processed "health foods" and rely instead on honest, "old-fashioned," whole-food sources of nutrients.
You can crush ice yourself by putting it in a cloth bag and whacking it with a hammer.
me , he , my three , , and -- and the one we lost