I blatantly ripped off an idea from a mama that's on a message board with me. (Her blog is here.)
Basically, I have made "chore books" for each of my two older kids. Abbie has a magnetic "responsiblity chart" (or, as she calls it, "my sponsitility charp". I love that kid.). So each page in their chore book represents one day; the top half of the page is morning chores, the bottom half is evening chores. If they finish their assigned chores before it's time for school (or errands, or whatever I have planned) or bedtime, they get a dollar in play money in their chore bank. Then, when they have money saved up, they "pay" me for a fun thing from the chore store. Now, let me clarify, that it's not like we never do anything fun otherwise. For instance, one of the events in the chore store is "go to the pool"...we do sometimes just GO. Or to the ocean, or to the playground. But I really like instilling in them the "work before play" mindset. And in response to Kris, who commented, "You must hate baking as much as I do", the answer is yes....yes, I do. Also, it's not likely that on any given day I'd have the right ingredients around to "bake a treat", whereas the playground is around the corner and open all the time!
If they don't finish their chores before the assigned time, they don't get the money. They still have to finish the chores later, though. Also, if I ask, "Are your chores done?" and they say yes and they've missed one (like picking up dirty clothes and putting them in the hamper. Every. day.), they don't get their money. I don't make a big deal out of it, just usually say, "Well, we'll try harder next time, right?"
This is, by far, the best-working chore system I've ever tried. Thank you, Sarah!