This is a WONDERFUL way to encourage your children (and your self) to do a better job.
My husband was telling me about one of the secrets to Walt Disney's success in making movies was to encourage his cartoonists to one up themselves.
So they would bring Mr. Disney a completed set, and Mr. Disney, without even looking at it, would ask them to one up themselves. They were to look and find one thing that they could improve or make better. After one uping themselves until they really could not one up one more time, Mr. Disney would then look at the product, and RARELY would he have to give any input.
I am not sure if there is any truth to that, or if it is just another urban legend. But I do know that doing this has REALLY helped make my children and myself better.
Whenever my children say they are done cleaning their zone, I tell them to one up themselves. I keep saying this until they say there is nothing left to one up. Usually their one-ups consist of picking up a piece of trash that they had overlooked in their rush to get things done.
As they get older, on-ups may consist of things like: changing the napkins at the table to be fresh, cutting some flowers from the garden for the table, changing the sheets on a bed, fluffing the pillows, lighting a candle.... well you get the idea.
I usually try to do this with everything I do. I will re-read and re-write blog posts and emails several times before they are actually posted/sent. Even when I use a public restroom, I will grab a paper towel and wipe down the counter if it is messy. You'll never know what an example for Christ you can be doing that.
We have been doing this for a while, and as soon as my oldest (8yr daughter) was done sweeping the floor, I heard her muffle to herself "What can I do to one up this?" :D She then proceeded to straighten the chairs at the table. :D