In order to become better at oral communication, students need practice—lots! There is no getting around this. Both in terms of input and in terms of output. Such practice helps not only with fluency but with accuracy as well. But as well as allowing for student practice of different functions in English, you can also help draw student attention to some of the aspects of communication. In Communication Spotlight, for instance, students are explicitly introduced to some of the different communication strategies employed in English, strategies that are quite different from those of Japanese. This is a focus too of the Communication Spotlight: Business series. Having students know how to use some of these strategies can considerably increase their confidence in going into communicative situations where their understanding is partial at best. You can also draw student attention to patterns of discourse; many conversations follow quite standard patterns. This is something done in Step Into English. Finally, you can provide students with stock phrases or conversation gambits which they can use in particular situations, an aspect treated by all our communication texts. And as much as possible speaking tasks should be personalized, allowing students to talk about their worlds and situations and draw out the words and language structures they need to do this.
And re. that practice thing… the classroom of course cannot provide anywhere enough practice time. So in addition to extra listening practice and other homework tasks, with Communication Spotlight there are also separate DVDs available which contain a video for each unit and accompanying exercises. These videos are also available through the Communication Spotlight with EnglishCentral Courseware versions of the texts, where in addition to the Spotlight videos, students have access to two other videos per unit and to EnglishCentral's voice recognition and vocabulary learning systems (and teachers access to an LMS). And of course encourage your students to get out there and use English as much as they can!