5 teaspoons of instant coffee powder: use one without sugar and creamer.
Since hot water melts coffee particles, don't worry about coarse coffee.
It doesn't matter what kind of sugar it is and if the amount of sugar is too small, it will not foam well, so add enough.
You should use very hot water to make the foam rise quickly. When the liquid cools, the foam will be made very slowly.
If there is too much water, it will take a long time to foam. Only add enough to melt the coffee.
Start stirring by hand whisk!
Since the amount of liquid is small, you must tilt the bowl to whip it so that you can whip it well.
Stir while drawing a large circle to add the air in the liquid
About 2 minutes
About 5 minutes
About 8 minutes later ... Almost done !!
When you drop it, the marks remain intact, you are done.
I think it's a good balance to pour 2/3 of the milk and 1/3 of the foam