Firebug
Laura Gordon, www.RytechSites.com

I made this presentation at the JoomlaNYC User group meeting on December 8, 2011.

Firebug is a very powerful tool that helps me to modify any template / design to my client's wishes.  Without it I would be completely blind.  By using it, I get the 'secrets' behind the website, how it is built, and how I can modify it.