I've been alternating between 15 minutes of cleaning and 15 minutes of resting. I got the idea to do this from Fly Lady. She is always saying to "set a timer."
This has done wonders for my house since I am keeping up with the regular chores and even getting to all the projects that I "didn't have time for" before (like cleaning out my closets and organizing my drawers).
It's also done wonders for my mental health since I am no longer discouraged by all the things that need to be done and I'm not overwhelmed by the prospect of cleaning without any end in sight.
I only start this alternating after we are done with school for the day, when I see the chores piling up and when have a few hours to kill (like in the afternoon once Avril goes down for a nap).
Before I started timing myself, I just cleaned and cleaned till it was all done and I dropped. But I find it easier to talk myself into fifteen minutes and right about the time I am feeling any strain from the work (Braxton Hicks are startin these days), the timer goes off and it's time to sit and rest again.
Watching the clock while I clean has an additional benefit. I now know just how long it takes to clean certain things in my home now and it's much easier to bring myself to do them knowing how very little time they really take (though it often feels like chores take much longer).
For instance, it takes three minutes to unload the dishwasher. That's it. Seriously. It is probably the same for you, too. And it takes three - four minutes more to load it again.
It usually takes ten minutes to do pots and pans. Interestingly enough, this is the part I don't mind as much. It's the loading and unloading that I really hate, even though it takes less than half the time than it takes to hand wash the pots.
It takes fifteen minutes (almost exactly) to clean my kitchen from "a state of emergency" messiness to near perfection. Add only five to ten more minutes to sweep and quick mop my kitchen floor to a shine. This is hard to believe, but it's true. It always felt like this took an hour, but it actually only takes fifteen minutes.
It takes three minutes to clean my bathroom doing everything but the serious, down and dirty scrubbing. That's it. Three minutes.
And it takes about five minutes to wash, dry and fold a load of laundry as I take it out of the dryer. If I wait to fold the clothes out of the basket the next day, for some reason, it takes twice as long.