Ironically after months of trying and failing to, alcohol was one of the major factors.
1) If you have blackout blinds/curtains, don't use them. Leave them open overnight.
2) If possible, sleep in a position that allows maximum sunlight exposure, preferably direct.
3) Never try to sleep earlier, only later - forcing yourself to sleep an hour early will be more difficult to adjust to than staying up 2 hours lster each night until you loop back around.
4) Set alarms for sunrise or shortly after it - even if you snooze it at first, your mind will be alerted when your alarm is nearing its noise based on the relative time of day if you get woken up by the alarm often. Pavlovian conditioning basically.
5) If you drink, drink your last drink before bed, around 8 hours before you have to wake up.