Compose a handout that consists of twelve idioms you wish your class to learn. Make sure each idiom is followed a short explanation of its meaning and an example of its usage. Make a copy for each of your students.
Demonstrate the twelve idioms to your students. A example would be the idiom "to catch." Explain its meaning. "To catch" means to ride or board. Follow this with a model of its usage, as in "I will catch the train." Finally, give a sequence of cues by which students can apply the idiom you have given them. A cue would be "I will ride the four-thirty bus." Students would reply, "I will catch the four-thirty bus."
Divide the class into three groups and assign each group four idioms. Allow them ten minutes to write a short dialogue that involves an exchange of their idioms between speakers. Attend to each group as they prepare in case they encounter any difficulties or misunderstandings in usage.
Select an order in which each group will present its dialogue. After each presentation allow a short time for questions or comments on the performance of the idioms; then begin the next group's presentation, until all the dialogues have been performed and discussed. Students may discover similarities between idioms used in their native languages and those found in English. They may also have interesting stories about idioms being misused or misunderstood.