The Command+Tab keyboard shortcut is useful for quickly switching the active window, but combined with the Option key, it can also open new and currently minimised windows as well.
Since Mac apps can be open without any windows present, Command+Tab brings up a list of not just open windows, but open apps. For apps that are open but currently window-less, you can open a new window by Command+Tabbing to the app, then holding down Option and releasing Command. A new window will pop right up. If the app currently has one minimised window, this will bring up the minimised window instead. If you use the Application Switcher a lot, it's convenient to have a new window only one more key away. Check out the video above to see the shortcut in action.