Frothing milk manually
Mechanical milk frother
With a mechanical milk frother, you use a wide, flat strainer to froth milk. Pour cold milk into the pitcher and place the lid on top. Now move the handle that's attached to the strainer up and down in a constant rhythm. This way, the strainer will move up and down through the milk. You'll feel the milk getting slightly thicker all te time. Keep going until the foam has the desired thickness. Thanks to the large strainer, this will happen pretty quickly. Put the milk foam in the microwave for a second to heat it.
A battery-powered whisk takes the whisking work out of your hands. First, you heat the milk in a pan until it begins to evaporate. Next, you put the whisk into the milk and press the button. The spiral will start rotating very fast, frothing the milk. Compared to a regular whisk, the battery-powered whisk makes faster and more constant rotating movements. This creates small air bubbles, automatically giving the foam a more rigid structure. It will take a while until you get the desired result, though.
With a whisk
Whisking up milk with a whisk is a classical form of frothing milk. Pour milk into a saucepan and put it on the stove. Keep heating the milk until it begins to evaporate, then turn off the heat. Grab the whisk and start whisking. This will work best if you hold the pan at a slight angle. The longer you whisk, the more foam will appear. No matter how hard you try though, the foam will never get very rigid. This is because large air bubbles are created during whisking, which will pop again soon.