Another runner posted a favorite smoothie recipe. I'm sure it's good, but I found the precision off-putting. Here's my infallible recipe for the perfect smoothie- and you already have the ingredients at home!
Take whatever various forms of fruit (fresh, canned or frozen) you have lying around the house. Throw them in a blender with whatever juice or juice concentrate you've got. Do NOT, I repeat, Do NOT measure anything! ;-)
Add one or more "creamy" bases: milk, yogurt, tofu, ice cream... whatever you've got. If desired, a little sweetener: I go with whatever (fruit) flavor Torani syrup is at hand.
Optional: Egg substitutes (or raw eggs if you want to live dangerously) or whatever is available that looks interesting.
Try to get the lid on the blender if you can.
Every batch is a wonderfully unique, once-in-a-lifetime treat. Healthy too! In the rare case where it isn't perfect- divide in half and keep adding things until it is. Occasionally you may even end up with enough to share!