Do everything without whining, complaining or arguing. Every one has their own jar. Start off the week with a set amount of quarters in each jar. If they are caught whining or complaining, they lose a quarter. At the end of the week, they get the money that's left or you could put it towards an activity.
Fun idea: If you don't pick something up after one warning, this mom confiscates it and puts it in a "ransom box." The only way you can get it back is to draw a task from the envelope attached to the box lid. Her tasks are hilarious!