Cut/Copy the whole line in your editor
When you execute the "Edit" → "Cut" / "Copy" command (or press the according shortcut) in your editor without selecting anything, the whole line will be cut/copied. This works at least in VSCode, Sublime Text 3 and JetBrains IDEs. Unfortunately, it does not work in Notepad++ or TextMate.
I've learned about this from this video, which provides other useful editor tips and tricks for IntelliJ IDEA.