If you'd rather not take your hands off the keyboard to access the Mac menu bar, you can execute any menu command using a keyboard shortcut. You can then use the arrow keys to navigate through the menu items and Return to select one. You can do something similar with the Dock as well.
If you want to go beyond System Preferences and change other settings on your Mac, you can do so with the Terminal window. But TinkerTool makes it even easier by giving you a list of potential settings and a user interface to make the changes without typing.