Leo over at zenhabits.net, a great site BTW, has a fantastic list about keeping a simple home with kids.
One of my favorite tips and something I try to do every night is number 19, Clean Before Bed.
I also do a quick clean-up right before I go to bed, getting any little things the little ones forgot to put away. It makes my mornings much more pleasant.
Waking up to a tidy house is a great way to start the morning, seeing dirty dishes in the sink and toys on the floor can really sap your energy.