I, too, have used it for well over twenty years after having -- once -- spending hours to get a broken plug removed and having to run a tap to get decent threads back into an iron head.
I prep the plugs the night before: inspect for electrode alignment; perfect the gap (per experience, not just spec); use DOW silicone dielectric on high tension cable end; use PERMATEX copper-based anti-seize paste on last few threads (AWAY from electrodes), carefully wiping on a thin film.
And I like to run a "cleaner" tap through cylinder head sparkplug threads prior to installation of new plugs.
And torque to spec, re-torquing after a few hundred miles when vehicle is known to have a problem with plugs seating properly.
I prep the plugs the night before: inspect for electrode alignment; perfect the gap (per experience, not just spec); use DOW silicone dielectric on high tension cable end; use PERMATEX copper-based anti-seize paste on last few threads (AWAY from electrodes), carefully wiping on a thin film.
And I like to run a "cleaner" tap through cylinder head sparkplug threads prior to installation of new plugs.
And torque to spec, re-torquing after a few hundred miles when vehicle is known to have a problem with plugs seating properly.