Famous Vocal Techniques

I'd really like to know how some famous vocalists get their unique sound. There was a great article discussing this, but I lost it. If you happen to know any secret tricks, please post them here (along with the vocalist who made it work). For example:

ROBERT PLANT (solo albums & Led Zeppelin's later years): 60ms delay and "compress the hell out of it."

I was thinking about compiling a cheat sheet so that when a client comes in and says "I want to sound like Ozzy on Paranoid", I don't have to figure it out every time. Thanks!