I was a little bit rushed when I responded to this question at first, so I didn’t put in some detail that might have made it a more useful answer.
When I say to “change your system” I mean, for example, to forget about an alarm clock in general. I have a bedroom clock, and I do refer to it from time to time (no pun intended), but I almost never set an alarm. Only in extreme cases when I have to, say, get up at 4 AM to catch a plane, for example, will I use the alarm. For day to day use – and for getting to work on time – I just wake up when I wake up, and my morning routine is built to give me plenty of spare time before I have to dash out the door to avoid being late for work.
But the system that gets me there is: knowing about how much time I will need to sleep every day to wake up – on my own, with no external prompting – on time to get a shower, pack a lunch, and spend some time relaxing before I leave the house for the day. On the times when I really do sleep in late (or in the winter, when I have to shovel the driveway before I leave for work), the only thing sacrificed is my “lounge on the couch with Facebook and Fluther” before leaving, and that’s a totally flexible time.
Don’t get me wrong: I don’t like to bounce out of bed every morning, either! Left to my own devices, I can easily read in bed between occasional snoozes, and spend hours before I “get up to start the day”. But on weekdays I’m out of bed by 6:30 on most mornings (sometimes earlier) and only occasionally as late as 7 AM if I had a particularly late night the day before.
Part of the reason this system works for me – as it may work for you, too – is that I don’t have a tremendous amount of willpower to will myself to do things that I would prefer not to do. (Conversely, not enough willpower to avoid doing things that I like to do, but shouldn’t.) So the system is now… just a habit. A workable system that becomes a habit takes zero effort to achieve.