I am a Phonetics teacher and am teaching linking /w/ and /j/ at the moment. Have you got any text to practise this kind of simplification?

I wonder what your students' first language is. Since native speakers don't normally use such linking semivowels, this is not a topic I would teach! And I don't understand how it could be seen as a "simplification". Perhaps I have misunderstood your question.

Cruttenden is being rather naughty here in his phonetic notation. The IPA symbols [ʲ, ʷ] are properly no more than diacritics, indicating palatalization and labialization respectively. He, though, is obviously using them to denote very short, transitional, non-phonemic glides.

I suppose he is right in saying that these not-quite-segments may sometimes be “heard”, since experience shows that some naïve transcribers are convinced that they exist. Personally, I take the line that they are figments of our imagination: the supposed “[ʲ]” in my arms merely represents the point of maximum upward excursus of the tongue body as it moves from [a] through [ɪ] towards [ɑ]. How could one possibly detect the presence vs. absence of this entity on a spectrogram?

If it meant anything, it would presumably mean that some small part of the aɪ is to be regarded as falling in the arms syllable rather than the my syllable. But we do not say *maɪ jɑːmz, as evidenced by minimal pairs such as Cruttenden’s I earn vs. I yearn: there is no phonological (phonemic, linguistic) j present in my arms or I earn.

And there’s no w in two evils (see below).

In this respect English differs from, for example, Serbian, which obligatorily inserts a phoneme j between i and a following vowel, as reflected in the spelling Srbija (not *Srbia): the syllables are sr . bi . ja.

Whatever we conclude from this discussion, I can certainly see no case for wasting any time in the EFL classroom on teaching such a dubious topic.