I'm a freelance writer and what works well for me is:
After taking kids to school do quick tidy up of breakfast stuff, put on load of laundry, walk dog.
Then sit down to work by about 9.45 (I have separate office in attic.)
Break for lunch about 1, when I hang up wet laundry.
Try to be back at desk by 1.30 ... but this is where the schedule sometimes slips and I get distracted .. and work until time to pick up kids from school (usually 3.30, sometimes later).
Do any other household chores, working in garden etc while kids are at home, including food shopping (they come too).
If I have a really tight deadline, I start work as soon as kids are at school and leave all housework until they get back -- including tidying up breakfast!
I almost never work after dc are in bed as am usually too knackered myself. And rarely work in school holidays as don't have childcare.Have tried and ended up over-relying on TV to keep them occupied while I made phone calls etc.
If I have other stuff to do e.g. go to hairdresser I usually plan that for the afternoon-- it is easier knowing I have done 3 solid billable work hours in morning.
And I occasionally take days off to do nice things.
I think the trick is to use the time when dc are around to do non-work jobs so you can concentrate fully when they are out of the way.