Overview

Not the most modern and useful thing, but a nice screen saver can have a positive effect.

• To chose a different screen saver from the pre-existent ones, from the Apple menu, choose System Preferences, then click Desktop & Screen Saver. Or simply right click on the desktop then chose Change Desktop Background.. (background, yes) then select the Screen Saver tab.
• To personalise the screen saver with your custom photo(s), create a folder under ~/Library/Screen\ Savers and place your photos there. Then, from the Screen Saver preferences, select your folder as the source and how you want them displayed. If your folder is not in the drop-down list, just choose it manually:

• Check the size of the existent screen savers to make sure it will be displayed correctly. A good choice would be 3200 X 2000 pixels