Well, as a working mom with kids, the Almighty Schedule is key.
DO what you are supposed to do, damn it, WHEN you are supposed to do it.
As the title suggests, however, there are less than perfect days. Where boys--and probably girls but I haven't experience in that field--are concerned, that is a capital F Frequently.
I hate playing catch up. I hate the stress, even though I can perform well under it. I prefer to tighten my timeline and create a schedule for myself that has me well ahead of the actual deadline. Incrementally working ahead, so to speak. Of course, I'm a firm believer in Scotty Logic.
"We haven't got six hours!"
Of course you only need two, but you anticipate problems and ask for six. (**I'm not suggesting you ask for triple the time you think you need, but hours are much shorter than months so the analogy works...) When you get the job done in two and a half hours, you have a half hour to recheck, and you're still looking like a hero done in well under the original time.
So my advice, work ahead so you don't scramble and work sloppy when time grows short.
Better to have time to reflect on the job at the end than to hope your editor will fix the slop you turned in. This IS your dream career, right? No excuses... own that bitch.
Staying focused (aromatherapy or music or whatever works for you), don't allow distractions (turn off FB and the phone), and spending a few minutes thinking ahead of where you are actually at writing wise will help pave the way.