This is a good tip. There's no set up needed, though - it's on by default. The above works well for iPhones with Touch ID.
On iPhone X, clicking the right button 5 times disables Face ID, but also invokes Emergency Call which makes a loud noise. An alternative is to simultaneously hold down the right button and one of the volume buttons until the power-off screen is displayed (and haptic feedback is given). The power-off screen can be dismissed by pressing the right button again, so this procedure can be silently done without taking your phone out of your pocket.
In case your hands are..well, tied, another alternative is saying “hey Siri, whose phone is this?” - pulls up your contact card and disables biometric unlock.
On iPhone X, clicking the right button 5 times disables Face ID, but also invokes Emergency Call which makes a loud noise. An alternative is to simultaneously hold down the right button and one of the volume buttons until the power-off screen is displayed (and haptic feedback is given). The power-off screen can be dismissed by pressing the right button again, so this procedure can be silently done without taking your phone out of your pocket.
Source: https://www.imore.com/how-quickly-disable-face-id-iphone-x