Too low is never mesured in your mothers opinion.... I can tell you that much.
Its to the point where if i pull up my boxers, but wear my pants ar my normal wasteline, she gets pissed and calls my "saggy" pants gross. But she doesnt like it when I tell her she is biased because reall my boxers are just high, my pants are at the right level...
Anyways, I normaly wear mine comfortable around the bum. thats about 1/3 from the top.