The bigger the company, the easier it is to do this. I try to track major things that either avoid expenditure or save money while improving services or eliminating useless spending.

Generally, I'm able to hit 3-4x salary. Once I was able to save the place 10-15x my salary by aggressively decommissioning some ancient, expensive to maintain legacy applications. Of course, this work is usually a team effort... but it's still a good feeling.