I wanted a quick way to visually distinguish DONE tasks from tasks I still need to do. This handy snippet from the Emacs Org-mode mailing list does the trick by striking through the headlines for DONE tasks.

Here’s the code:

(setq org-fontify-done-headline t)
(custom-set-faces
 '(org-done ((t (:foreground "PaleGreen"   
                 :weight normal
                 :strike-through t))))
 '(org-headline-done 
            ((((class color) (min-colors 16) (background dark)) 
               (:foreground "LightSalmon" :strike-through t)))))

View my Emacs configuration