This a real favorite at our house because we LOVE fruit and I HATE to waste food:
I buy 1 dozen small-medium sized bananas each week. Peel and save all uneaten or spotting bananas in the freezer. I break each peeled and uneaten banana into 4th or 5ths. I use freezer bags, but you can use anything really. I re-use the bags. If the bags are ever empty I just put them back in the freezer so they won't get tossed.
Freeze any fruit (grapes, kiwis, whole washed strawberries---pluck greens or stems later if in a hurry) which is uneaten and going to spoil. I do this a lot with apples (or oranges) which have been sliced and turn brown that no one wants to eat. In the summer I do this with melons which will rot before we can eat them all. I slice them into small squares and then freeze.
When you are ready to make your shake: Add about one cup of frozen fruit with one cup of juice or milk to your blender. Blend it up. Once it is mixed well add another cup of fruit and liquid, if desired. It can be all frozen fruit or some unfrozen as well. The more frozen odds and ends you use the more it is like a creamy ice cream mix. Turn off the blended and use a spoon to push the frozen pieces to the bottom, if needed.
If it needs to be sweeter add honey or brown sugar. Another thing I do sometimes is add half a cup plain, vanilla, or any other flavor of yogurt I have on hand. I also like to add a 1/4 cup of flax seed or wheat germ.
I don't use a measuring cup when I do this. I am just estimating here. So do whatever works for you, your blender, and family. I just have a basic blender. I make a whole pitcher of this and it doesn't go to waste. I just put the whole pitcher (blender) in the fridge if there is any left, and it is good for a few hours or more. Both boys love this shake with straws or a spoon. They love to help make it, too. But mostly they love to eat it.
P.S. Sometimes they prefer to eat the frozen items alone and not in a shake. On a hot summer day there is nothing tastier than frozen grapes or a frozen banana when everyone is too tired to make a shake.