Cutting back on printing is key, but using various fonts can save ink.
A 2010 study at University of Wisconsin – Green Bay, showed they saved $10,000 by switching all default printing to Century Gothic (this blog post is set in this font face). They say it uses 30% less than Arial.
This article explains others fonts to use to save ink mentioning a study by Matt Robinson to determine ink usage of various typefonts. His study shows Garamond followed by Courier are the most economic.
The ecofont (the one with hole!) is even better and you can download the Ecofont Vera Sans regular for free if you register.
In my opinion, reducing the font size will save much more toner than changing the typeface (print in two columns if the lines get too long to be readable). Using the draft mode of the printer is also very effective.
I never use the ecofont because the letters look gray with the holes in them. If I want to have grey letters, I choose grey as the font color in my word processor while I work on a draft, and change it to black for the final version. That way I can the layout and hyphenation and pagination do not change (as they would when I change from ecofont to another typeface for the final version).
Good point, reducing font size is a plus & using gray fonts until final print! of course making sure you select and print only what you need.