I haven't used the alarm on my bedside clock in years. Over the years, I've noticed that every time I did use the alarm, I automatically woke up 5-15 minutes before it went off. So I tried just telling myself what time I want to wake up, now I'm usually within 5-10 minutes of that time.

I've been getting up at 5:30 am to go to the gym before work for 3 years now. I can count the times I've overslept on one hand. On occasions I have changed my mind about going to the gym, I still woke up around 5:30, then decided the gym wasn't going to happen that day, and slept for a little longer, still without using an alarm.