I'm not sure to what extent the makers of TOEIC go out of their way to put idioms on their test, but such idioms do occur often in everyday speech and perhaps reflect an anglophone sense of metaphor, which can be completely baffling to EFL learners. While I don't think the TOEIC or TOEFL or other such standardized EFL tests should be a requirement for everyone, they might help 'non-native' EFL teachers track and guide their own development.
In Japan, many teachers refuse to model any oral English at all, often citing lack of self-confidence. I think we need to get beyond this. Indeed, getting beyond this impasse would be a big step forward. On the other hand, native speaker types might spend more time learning how to teach formally described aspects of language, such as grammar, idiomatic vocabulary, and pronunciation (applied phonology).They might also do well to familiarize themselves with the syllabuses and vocabulary lists their students have studied at the secondary level.
Here is an article online to help practice common English idioms:
Excerpt (see page at link for the complete list of idioms):
30 Common English Idioms
TOEIC and TOEFL Takers; Get Your Feet Wet on These!
By Kelly Roell, About.com Guide
Learning English isn't all it's cracked up to be (Learning English is difficult). First, grammar muddies the waters (makes things unclear), but idiomatic expressions only add fuel to the fire (make things worse).
If you’re taking the TOEFL or the TOEIC, read this list of common idiomatic expressions before you take the test. They may just help your English language acquisition soar (get much better).
Common English Idioms
1. “24/7”: Twenty-four hours a day; seven days a week; all the time; constantly
My little sister irritates me 24/7!
End of excerpt, see link above for full list