I try to get as many servings of fruits and vegetables throughout the day as I can. A smoothie can be a yummy way to get your greens and fruits in! They are hydrating, can make your skin glow and give a great energy bump to your mornings!
One of the biggest problems I have found though is that I either don't put enough veggies in, or it turns out to be a total sugar/calorie bomb with all of the extras I tend to add for variety.
I once read that the ingredients inside your blender should be the same amount that you would eat on a plate. So as you add your ingredients, keep in mind that as you blend, the ingredients will easily shrink and condense into a "1 Glass" serving. But you might be eating alot more than one serving.