Glad to see so many people obsessed with the idea of early rising
This habit is easy to get, I myself acquired it dozens of time
Seriously though, I've found that the most productive way to acquire it is to use as many "receipies", tricks and approaches you may find, all at the same time.
I ended up collecting most practical from those tricks that I've learned and put them here:
How to Wake Up Early. I have more unpublished tricks than published still, so it's a work in progress.
I don't wake up at the same time every day, I try to regulate the amount of time I sleep, not the wake up time itself. When I go to bed by 11pm I wake up at 5-30am. If I got later, say 1am, I wake up at 7-7:30am.