I make smoothies with yogurt. I usually don't measure, but I put in low-fat vanilla yogurt, add a few frozen strawberries, a handfull of frozen blueberries or peaches, a half banana and some juice and blend together. I usually start with vanilla yogurt, and add whatever I have around the house. I use canned fruit, also. Just try adding whatever you have and if you need it sweeter, you can add a little sugar to it once it has all been blended up and you have tasted it. Then add sugar and blend again. My kids love these and so do I.
yolo