Once you hear a click, it's tightened. Kind of like a torque-ratchet system - once you hear that first click, it's as tight as it is going to get. You can continue to turn it and hear more and more clicks but it doesn't get any tighter.
I do 3 clicks just to be sure. I did 4 one day and got worried that I screwed it up so I loosened it and started over. One day I was there 15 minutes trying to get it right.