The two main ideas that stood out to me the most were:
I. For better motivation provide three levels of rewards
1) small rewards are immediate- a sticker
2) medium rewards require some saving up towards- a few days
3) large rewards take longer to save towards- a week or two
II. Mix of structured reward times and random reward times so that they stay motivated.
This is what we decided to implement in our homeschool:
Structured Reward Times
They each have a clipboard with a weekly lesson chart that they highlight as they finish
For each school lesson they finish they get a popsicle stick which goes into a pocket chart
Random Reward Times
If I see them all on task I will offer them a reward from the small reward bucket
Sometimes I will give them an "If you...." challenge that can earn them a small reward or a stick
(ie: if you finish your morning routine without me telling you)
Rewards
For the small rewards we have stickers, party favors, erasers, pencils, balloons, etc.
For the medium rewards we have a "store" where they can redeem sticks every Thursday. I lay out the prizes and they can buy them for various prices. (ie: 1 stick= something from the small reward box. 5 sticks= flashlight, journal, glitter pens, note pads, and other things purchased for $1-$3.
For the large reward they can save up their sticks to go out with dad or mom. This is a one on one reward time. They can choose from a limited variety of activities (ie: ice cream, bowling, hiking, baking time, etc).
~Disclaimer~ I am not looking over this because I am way tired. Also, all the pictures were found on the web because my camera was lost by a busy three year old. At least it wasn't my wedding ring this time!!