I actually feel for the people below me, and try to walk very quietly around my apartment. Unless, of course, I am moving something.
I do the same, as much as could reasonably be expected. I'm not a "heel-walker" to begin with, but I do make a conscious effort to walk more quietly than normal when I'm at home.
Then again, things like footsteps, opening/closing doors, vacuuming, etc., generally don't bother me very much; for some reason, it's only music/TV/etc. that does it.
