I find that making myself wake up >1hr before my kids is a giant boon to my happiness/productivity. All bets are off if one of them didn't sleep through the night for some reason, though.
Hm, my kids are the same as me: they get up late as well. And if the oldest wakes me up early I just tell her to go back to bed or her chamber since I want to sleep some more.
That's improved my ability to get up early - if I want to get something done in the morning or just get some quiet time to myself, I have to do it before the boy wakes.
One thing I found as well is that it's easier for me to put an alarm clock slightly before he wakes up, vs. being woken up by him!