Command–Space bar: Show or hide the Spotlight search field.To close all windows of the app, press Option-Command-W. Command-O: Open the selected item, or open a dialog to select a file to open.To minimize all windows of the front app, press Option-Command-M. Command-M: Minimize the front window to the Dock.
To view the front app but hide all other apps, press Option-Command-H. To find the previous occurrence, press Shift-Command-G.
In some apps, you can undo and redo multiple commands. You can then press Shift-Command-Z to Redo, reversing the undo command.
Command-X: Cut the selected item and copy it to the Clipboard.
