Several months ago, we began using an incentive system to encourage Jake & Mallory toward good behavior & doing their chores without complaining. We snagged this idea from a friend's blog, & it has really worked well for everyone.
Ideally, we sit down twice a day, morning & bedtime, to go over the rewards each kid has earned so far. When mornings are busy, we just do it all at bedtime, but it gets hard for them to remember the stuff from the beginning of the day. I need to work harder to fit in it at the right time. Each child has a large jar to fill with rewards from each of the six "task" jars.
A button is earned from the potty jar for a dry pull-up (Jake) or underwear (Mal) in the morning, & then another can be earned for a full day without accidents. A colorful bead can be earned from the bed jar for making their beds when told in the morning (to the best of their abilities). Two buttons from the toothbrush jar can be earned daily for completing that task without any resistance. One pom-pom from the toy jar is given to those who clean up well. Pom-poms from the mouth jar aren't necessarily given daily, but just whenever Mommy notices one of them being especially polite with what they say. The thumbs up jar, the most coveted of all, holds jingle bells, given at random times for good behavior that goes above & beyond.
When their rewards reach the first line on their big jar, that child gets to pick out a prize or toy of some kind from Target (or another store they like). Reaching the second line earns them a trip to the ice cream shop. When the top line is achieved, it's Chuck E. Cheese time! They usually earn rewards at a pretty similar rate, although it varies day to day, so we've been able to get by with group trips for ice cream & CEC so far.
This is by no means a perfect system, but it does help encourage & reward their good behavior. Good job, guys!