Nothing. I'm still on the original OE pads and rotors. I've only had to stand on my brakes a handful of times; and no change in brake smoothness resulted. The rest of the time, I'm a "coaster" and downshift, or just let the engine do the downshifting, which it does rather well, by the way. I think I'm going to get 40K plus out of my pads at this rate; and my rotors will probably last as long as the car. (Unless I succumb to temptation and replace pads and rotors at the same time, with higher performance
aftermarket ones: I subscribe to all the "brakes threads" to keep informed on what's available and recommended; so far I have no favorite
aftermarket brand that I would choose over another.)