3 steps to make The perfect milkshake:
1º It should not carry much scum, that's why the milk is added after beating the fruit.
2º You must take 50% milk and 50% ripe fruit, banana or mango are my favorites. If the whipped fruit is very thick, like a paste, you can add a bit of water.
3º If you follow the steps above, it will have the right density to absorb it with a straw.