How do you toot your own horn silently?

The catch with enabling is that the more effective it is, so the better you do your job, the less other people know you helped.

When the best have accomplished their task, and their work is done,
The people all say "We have done it ourselves."
--Tao Te Ching, chapter 17

How do you measure helpingness? This is both for yourself (to see how you can do it more effectively) and to show others so you can get opportunities to help more people later. How do you show what you've done without pasting your name over something you've worked so hard to give somebody else ownership of and visibility by?