A large number of my students are English Language Learners (ELLs). ELLs have a tendency to take things literally. This activity helps students learn that there are figurative meanings as well.
In this activity, students write the idiom of the week. (I have an idiom of the week on display on a bulletin board in the classroom.) Students explain what the idiom actually means and then illustrate this meaning. This enables students to create word-picture associations. In the past, I have had students also illustrate the literal meaning of the idiom of the week, but I have learned that by having them do so, they then think that that meaning is important and get confused as to what the actual meaning of the idiom is. Besides which, the poster of the idiom of the week shows the literal meaning and I don't see the point in having the students be redundant and illustrate it again.