I have the same issue. Just too damn tired in the morning, does not matter when I go to bed, I'm just not a morning person. The time after 5-6am is where I sleep the hardest and where I dream. Winter is even worse because it's so dark and the clocks are set forward an hour so I'm technically getting up an hour earlier.
I like working night shifts though as they actually go with my natural clock. I can sleep in practically for as long as I want, get up, spend a bit of time in the house then go to work. I don't have to get up to go to work, I just need to go to work, because I'm already up. I don't get tired till around 4-5am. Even when I do go to bed early it's rare I fall asleep before midnight.
One habit I'm trying to get out of though is on my days off I tend to sleep in to the point where I get more than 8 hours of sleep. That's just a waste of time. Time already goes by fast enough as is, I don't need to be sleeping it away.