No one seems to have said it yet, but consistency. Waking up at the same time every day including weekends. Eventually, you just wake up early naturally. I get up at 5:30 am every day on the dot with zero alarm just because it’s when I wake up. And I’m never groggy, because I’ve adapted to it. It’s not early anymore it’s just when I wake up

I think the second half to this is that it can’t be a chore. You have to want to wake up. If you wake up and think about how much you hate being awake it will be all the harder