Recently had a friend ask me what this procedure is. There are standard ways of doing it and there are non-standard ways. You could go to the Play store and download a screenshots app like it’s 2007 or if you have a Samsung device you have options of the karate chop where you swipe your palm across the screen to take a screenshot.
The most standard way of doing things is holding the power and home button together. If your phone doesn’t have a home button like most are, then the capacitive touch home key applies.