Add all the ingredients to a powerful blender and blend until smooth.
Best when fresh, feel free to keep the smoothie in an airtight container in the fridge for up to 3 days. You can also freeze it and transfer to the fidge the night before you're going to consume the smoothie.
Notes
If you use frozen mango chunks and s frozen banana your smoothie will be so creamy, but you can also use fresh mango and a regular banana.
I prefer to use unsweetened milk because is healthier, but it's up to you. If your smoothie is not sweet, maybe the fruit was not ripe enough. Try to add 1 or 2 Medjool dates and blend again until smooth.
If you're using fresh fruit, but you want your smoothie to be cold, use cold milk or add some ice cubes before blending.
Add more or less milk, depending on how thick you want your smoothie.
Use a powerful blender if possible. If you don't have one, maybe it could be a good idea to add the fruit fresh instead of frozen. You can also add more milk if needed.