How do you make a good cappuccino?
There are multiple steps involved in making a good cappuccino:

Step 1: Find fresh coffee beans and grind them finely

For optimal taste, the coffee beans should be fresh and only slightly oxidized. It is important to use a high quality grinder that grinds the beans uniformly and finely. You should fill a portafilter with 18-21g of grounds and tamp the grounds.

Step 2: Pull the shot

Turn on the espresso machine, wait for it to heat up, and press the button to start the shot. The goal is to make ~40g of espresso in 25-30 seconds starting from when you initiated the pull.

Step 3: Steam the milk and pour

Pour milk into a carafe and use the steam wand to steam the milk. You want to aerate the milk, but not too much or too little. You want to avoid making macrobubbles and also heat up the milk so that the carafe is hot to the touch. Now pour the milk into the espresso, and you're done!