Also, they're a great way to sneak fruits into your diet. And making them at home is not only cheaper than going to the local juice shack, but you don't have to get out of your pajamas to enjoy one. It's a win-win!
My staple ingredients are: Ice, milk, sugar, yogurt (these are my favorite).
From there, I usually throw in whatever fruits I have laying around. Today was strawberries, blueberries, and half of a banana. I've also added peach, fresh and in syrup, and both work great.
Toss in the blender and enjoy your day.