0 Roll Up and Down a Window

When you double-click the title bar of a window, the default setting is to maximize a window. Since there's already a maximize button you can use for this, I always like to change the default setting to rolling up (or 'shading') a window when I double-click on its title bar.

1. Go to System > Preferences > Windows
2. In "Titlebar Action", select "Roll up" (or "Shade" where applicable), from the drop-down list.

Now you can roll up a window when you double-click its title bar, and roll it down by double-clicking the title bar again. Simple as that.