I serviced fire alarm panels for many years. I would often ask for the power to be disconnected as I usually didn't know where the disconnect was. Once assured the power was off I had a particular screwdriver that I would firmely seat in the 120 VAC screw on the termanal strip and then lean the screwdriver to one side until I contacted the cabinet. There were a few chunks missing from that screw driver.
My procedure when disconnecting power to a circuit is to first connect a means of identifying whether the circuit is dead or live (i.e., a radio, a lamp, and possibly a helper to tell me when things go off and on). I then disconnect the power and verify the circuit is dead. I then RECONNECT the power and verify that the circuit is live, then disconnect again (and verify it's dead). This helps guard against a simultaneous failure of the test scenario and serves as a double-verification that the circuit is indeed dead.
But before sacrificing your screwdriver, you *could* meter it. And even after metering, testing with the screwdriver as you do is a good idea. So is wearing PPE (personal protective equipment) so when the screwdriver shorts you aren't injured from flying molten metal.