Here's how you can change the size of your OS X desktop icons, and adjust their spacing. This can help free up space on your Mac's desktop. 1. Click anywhere on the desktop. 2. Hit Command-J to bring up the icon size menu. 3. You can use the menu to change the size of icons. 4. You can also adjust grid spacing.
For more, see the original article at the link below.
Make more elbow room on the desktop | Macworld