hold the S pen tip near the screen, click the S pen button, brings up a selection icon. Touch the small icon in the lower right end of the larger icon and it takes an image of the screen and opens it for editing.
I don't like the hand swipe - it's too easy to take a screenshot you don't want. I use the S-Pen. Fast and easy. (And if I'm using the phone for anything but a phone call, I probably have the pen in my hand anyway.)