Very impressive answers above me. Well, I am really a very heavy sleeper. Some people just are heavy sleepers (and now it has been answered why. that's a different discussion)
I set 4 to 5 alarms with a ringtone that makes my brain attentive. I use Ind vs Pak T20 world cup 2007 , final over commentary as my ringtone and every morning I wake up bcz it was really one hell of a intense situation and I so love cricket.
So just do something innovative like that and trust Alarms. They're invented to wake us up mate.
