#1 Barter Babysitting Services
I have a friend who I barter babysitting services with. My husband and I will watch her kids occasionally so she can go out with the girls and take a break or even just get some work done that otherwise would take 10x longer with the kids around, you know? She returns the favor for us. This works well because we really enjoy each others' kids. If you do this, obviously, make sure it is with someone you know well and trust and that your kids get along fine as well. I wouldn't do this with a chronic cancellor who would do this to only their advantage.
#2 Family Activities
Alright, now your eyes are REALLY rolling, aren't they? Seriously though, put a movie on for the kids and cook dinner together. Wash the dishes together. Fold clothes together (and do NOT say a word about how he's -or she's- folding a shirt the wrong way.) Even grocery shopping with the kids could apply here. During this time, you can converse and learn about each other. Discuss how your day went. Talk about your worries and your dreams.
A friend of mine sent a picture to me one day of her and her husband cooking together and said to me, "The couple that cooks together... Eats good and gets fat together!?!?" I thought it was just about the cutest picture and caption I'd ever seen in my life!
So in closing, it may not be a candle-lit dinner, movies, and a bed of roses with your legs shaking at the end of the night, but here's to hoping this will give you some ideas on how to incorporate some quality time with your partner into those busy mommy and daddy days when it seems impossible.