The most effective way to teach sound distinctions—the difference between two quite similar sounds—is to make the distinction crucial to understanding some message.
One way to do this is integrating the distinction into a spelling lesson. For example, the following does this:
"Number 1. Spell the word feet." /fiyt/
"Number 2. Spell the word fit." /fIt/
Before proceeding, it is necessary that the students already know the difference between the written words. The students take the spelling test knowing, as students often do on a spelling test, which words are going to be given. If the students hear nothing but these sentences (without the phonetic transcriptions, of course), the only way to differentiate between feet and fit (or other such minimal pairs) is by distinguishing the sounds /iy/ and /I/.
Sample materials and discussion: /iy/ and /I/ again
English has two high front vowels /iy/ and /I/, while many languages have only one high front vowel. As a result, when speakers of these languages learn English, they must learn to distinguish two vowels where their first language has only one.