This method is for using an espresso machine with steaming wand. If you don’t have an espresso machine, go to How to Froth Milk instead.

1. Prep for the steaming: Grind and tamp the espresso, but don’t pull it. Store your milk jug in the refrigerator: the colder the milk is the more time you have to get the right texture.  Or, rinse it in very cold water, dry and refrigerate for a few minutes. Fill your milk jug to just below the spout, about 3/4 cup, using very fresh whole milk (or oat milk for vegan). 
2. Make the espresso: Use your espresso machine to make two shots of espresso and pour it into a mug.
3. Steam the milk: Heat the steam wand. Once prepared, place the wand just below the surface of the milk about 1/2 inch from the side, tilting the jug slightly. Keep it in that position for about 5 to 10 seconds, slowly lowering the jug as the milk stretches (expands). Stretch the milk by about 20 to 25% in height for a Flat White, 30 to 35% for a Latte, or 30 to 50% for a Cappuccino, or 50% for a Macchiato. Once you’ve stretched the milk, raise the jug to bury the nozzle even further and tilt the pitcher just enough to get a spinning vortex, which incorporates the foam and turns it into a velvety microfoam (the exception is if you’re making a Macchiato, skip the spinning vortex part and just bury the nozzle, since you want a dry foam). Hold the nozzle still while the milk spins, until the temperature is about 150 degrees Fahrenheit. Using a pitcher with a temperature sticker is very helpful here. Use a thermometer or temperature sticker, or judge by when your hand can’t hold the pitcher for more than a few seconds.
4. Finish steaming: Turn off the steam before removing the wand from the jug. Wipe the wand with a clean cloth. Turn it on for 1 second to purge the nozzle.  Tap and swirl the pitcher to incorporate any bubbles on top. The final texture should look like wet paint or melted ice cream, smooth and velvety. You’ll use only about half of this quantity and can discard the rest (see the * note below). 
5. Pour the steamed milk into your coffee drink: Tap the milk container on counter and swirl it to break down any large bubbles. Pour milk into center of the espresso, ending with light foam. (The exception is with a Macchiato; you’ll just use a spoon to remove and add 1/4 cup dry foam to the top of your drink, instead of pouring in the microfoam.)