If you are a night owl, make sure that you don't spend your night hours watching television because your morning person spouse enjoys that. These are your best hours for getting work done productively. I don't know if for you it's because you like the quietness of night or the sense that you are breaking curfew. It may be a biological difference. But use it. Use what works for you.
If you are a morning person, get up and take advantage of this time. Seize the day! Get up before anyone else in your house does and sneak down and get in some hours before breakfast.
For me, the hardest work that I ever have to do is outlining/brainstorming a project. The second hardest work is actually doing a first draft. Then comes significant revision that requires new sections to be created. Other kinds of editing take a different kind of brain. So I try to prioritize the work that needs the most of my brain for my best hours.
It used to be that I was a morning person. I woke up at 5 and exercised, then hustled down to my office and got in an hour or an hour and a half of work before my kids woke up and my husband left for work in the day. Then I fit in some more work time in in the early afternoon when kids took naps. But now that my kids are older and I have one in each of the different leaving times, one before 7, one at 7:30 and one at 8:30, the whole morning from 6:30 when I wake up until 8:30 when the last one leaves is a bit chaotic. I can do work, but it tends not to be the work that I need all of my brain to do.
During off-hours I can look over work I did the day before and edit it. I can answer emails. I can make lists of things that need to be done the rest of the month. I can write short bits for publication on-line, or for my tumblr or blog. I can write race reports or some non-fiction. But I am too distracted to do much else, so I don't.
Once my youngest is out the door, however, it's to work on the hard stuff. I work for a couple of hours, take a lunch break, and then get in a couple more hours before my oldest son is home from high school. Then the house becomes noisy and chaotic again. My kids need me to be available for homework help, running errands, and talking over problems at school in the afternoon so I try to leave that time available if they need it.
In the morning, I am trying to make sure that everyone has what they need before they get out the door and that they remember anything they need to turn in, appointments during school, after school schedule, and so on.
I don't know what my life will be like when the kids are all out of the house. Maybe I will go back to being a morning person. Or maybe I will turn into a night owl. But I still think everyone has more productive hours and less productive hours. It can be tempting to use all your hours to deal with easier projects. Don't do this. Be self-disciplined enough to make sure that you move on to the hard stuff when it's time.