Ask HN: What gestures do you use on a daily basis?

I recently discovered that in Youtube (on android 8), I could double-tap (triple, 4x, 5x, etc) on the right or left of a full screen video to forward or rewind the video by 10 seconds for every tap after the 1st. For example, I could rewind the video by 60 seconds if I tapped the screen 7 times left of center.

For whatever reason, this greatly enhanced my use of Youtube, and got me thinking about other everyday gestures that I might have missed that either improve joy, efficiency, or productivity.

What gestures have you found in your life that are of profound significance to how you go about working or playing? Something along the lines of, if the gesture no longer worked, would irritate you for all time.

Mouse gestures, tapping, phone-flicking, all gestures are fair game.