So, we take a lot of screenshots here at Cult of Mac. Especially here in the Tips section, it seems like I’m always hitting Command-Shift-3 for a full screen picture or Command-Shift-4 for a selection of the windows I can drag across to select the image area.
Turns out that there’s a modifier for Command-Shift-4 that lets you take a screenshot of an individual window, or even one of those sheet things, a window that drops down from another window and is attached to it, as in the screenshot above.