MINIMIZING MULTIPLE WINDOWS AT ONCE

If you have three or four open windows in the same application and want to minimize them all to the Dock at once, just hold the Option key and double-click on the title bar of any one of them, and all open windows will go to the Dock. Be careful when you do this, because if you have 50 open windows, they're all headed to the Dock in a hurry, and there's no real undo for this. Worse yet, you'll eventually have to pull 50 very tiny icons from the Dock one by one (or if you're bright, just close the application, which closes the files in the Dock). So make sure that's really what you want to do before you Option-double-click.

All Word files minimized by Option-double-clicking