Besides the annual bleed and the occasional new pads & rotors, what do you guys do about disc brake maintenance? I never heard that there was anything to do, but I'm not getting the performance that I want from my Shimano XTs a few months after changing pads/rotors.

I was talking to somebody that said to run steel wool through the pads and wipe the rotors down with alcohol after every other ride. What should I be doing?