For many years I would hit the “Prt Scr” key on my keyboard and then paste the screen capture into Photoshop or whatever to play with. Even with multiple monitors the “Prt Scr” key captures everything displayed on all your monitors in one giant graphic.
The tip is to hold down the ALT key when pressing the “Prt Scr” key and you’ll get a screen shot of only your currently active application window!
Hopefully this tip will save you some cropping if you didn’t know about the ALT key combo.