Now that we own a Vitamix, smoothies have become a huge part of our daily meal. This is an easy way to add a lot of greens to my kids' meals and eat healthier. No additional sugar or artificial flavors required.
Typically, I add large amounts of green leafs and tone it down with some sweet and sour fruits. One thing to keep in mind if you want a healthy smoothie, is not to add a lot of sweet fruits, as they are high in sugar. But either way, they are filled with great nutrients.
p.s. Vitamix has become one of my favorite things I own in the kitchen. It is so powerful and quick to use. It creates a very smooth smoothie texture.