CCN, that story about teaching your son the difference between sounds by showing your face does sound familiar! This kind of explicit teaching can be so effective.
We have also found that, once each sound is learned, we can spell words to clarify the proper pronunciation.
The University of Iowa has a website that provides both video and cutaway animation video of the pronunciation of each phonogram. These can really help teach a kid to see how to pronounce and see the movements of the different sounds. http://www.uiowa.edu/~acadtech/phonetics/
