The trick is to set your alarm but put it, say, at the end of the hallway (providing it won’t wake anyone up). That means you’ll hear it, but you have to get up and hurry up to turn it off. Or else put it at the end of your room. As long as you have to get up. It helps if it’s a ringer you can’t stand (I know whenever I hear that “bleeeep bleeeep” I go insane), or if you want to rush to turn it off before it wakes up everyone else. If worse comes to worse, set two or three alarms at various points in your room, so that you have to walk around a bit to turn them off. Or set them 5 minutes between so even if you go and lay down you’re going to be up in 5 minutes anyways.
I also found that setting one alarm an hour before I had to get up, then another right when I did have to get up, helps alot, because then you’ve given yourself the illusion that you got extra sleep. Everyone loves waking up and looking at the clock and realising they’ve got an extra while to sleep—especially an hour.
