It's easy think we always have to do our very best: to polish everything before we let anyone hear it, to think that each time we play it must be representative of our finest effort after hours/days/years of practice.
There are times when it's important to present your finest performance. But sometimes, you just gotta mess around. If you have some friends to sight read with after dinner - do it! That's what Frederic and I did after a delicious salmon dinner at his new home in Connecticut. Doing that first 80% that we can do at whatever level we sight read can bring great joy.
Encourage your students to do the same - sight reading just for fun with you or with others. It can become the best of habits.
More information about Frederic can be found athttp://www.fredericchiu.com/