I love bananas, and they're a perfect smoothie ingredient since they thicken the smoothie so well. And, if you've got a banana that's a little beyond perfectly ripe, it's perfect for smoothies.
Straw-nana Smoothie
1 cup strawberry yogurt
1 cup milk
1 banana
Pinch salt
Splash vanilla extract
Add al the ingredients to your blender and blend until smooth.