It's all a matter of how you practice. Until I was comfortable with carrying one in the chamber, I just practiced drawing condition 3 until it was second nature. When I realized the gun wasn't going to go off by itself, especially with the safety on, I moved up to condition 2.
The Beretta is not designed for condition 1 like the 1911 is.
"What is the best way to carry the Beretta 92 ready to go if needed?"
Carry how you are comfortable, and practice, practice, practice.
One argument against not carrying with one in the chamber is, "what if you don't have both hands or don't have time to rack the slide?"
It only takes a fraction of a second to rack the slide, and if you don't have both hands, the attacker probably doesn't have his either.... someone like myself who used to train Judo/Jiu-Jitsu religiously is put in a very good position if the bad guy has a hold on you (not recommended to those who didn't wrestle, judo all through high school ;-) ).
The weapon is designed to have one in the chamber and is perfectly safe to do so with. With the safety on, the firing pin is blocked and the trigger will not engage the hammer. Also, even if you carry safety off, the long double-action trigger pull in a good holster will prevent discharge.