Have a perfect milkshake

Here's one suggestion on how to make a $5 milkshake

Banana? Yogurt? I don't think so.

How to make a perfect milkshake

Now, one scoop of ice cream is about 1/4 cup or 2 ounces, so the ratio is 3:1 3 ice cream to 1 milk.
You can use the ice cream scoop as a measuring cup for the milk

Here's Paula Deen's milkshake, which is one of the most popular milkshake recipes at Food Network.
I would skip the sugar altogether, I think there's too much sugar in most ice creams already.

MY perfect milkshake uses good, creamy vanilla ice cream (the kind of ice cream you would eat straight out of the package with pleasure) and full fat milk. Not cream.
There is no sugar added, nor yogurt, nor fruits.
I like it really cold, but smooth, so the ice cream should be soft (not melty), and THEN you can add a little crushed ice to make it colder.

There's no decoration on my perfect milkshake.

I can think of trying the yogurt-shake, and experimenting with infused milk... vanilla milk, ice cold, might produce a really, really delicious milkshake.