And this is why modern child psychology de-emphasizes praise.

As it was put to me in one of the attachment parenting classes, "If your children rely on your praise to know if they're doing well, what will they do when you're not around?"

My son is fifteen now, top of his class, loves to study and read, and in his entire life I've never once said, "Good job" to him.

The way you handle it is ask them to reflect on their accomplishment: What do you think about that? How did it make you feel? Etc.

And if you feel like you must use an exclamation, just a "Wow!" is perfect.

As was also shown to us in the classes, children don't seek your praise; they seek your attention (big difference).