I am in a similar situation. I would like to write in the morning, but my two young daughters often wake up at 6:30, and I’m really not willing (or able) to wake up even earlier to write. Once they wake up, all bets are off – the house is a maelstrom until they leave for school with my wife. Sometimes, I’ll manage to steal an hour or so during work hours to write, but on busy days (as it’s been the case lately) it’s impossible. Sometimes I can start my writing once they are in bed, but I also want to spend time with my wife, so oftentimes I don’t get to really write until after she goes to sleep as well (11’ish). My brain is toast at this time, so I use these times to write not-so-technical parts.
I guess what I’m saying is that my technique so far has been to write whenever I can :) It’s been impossible so far to find a fixed time for writing. Good luck.