Here is a classical story-telling technique:
Prepare a story and one that would not normally take more then 3-4 minutes to tell.
Explain to the students that you are going to tell them a story and that their job is to stop you, by asking a million questions about the story! You must answer all the questions however quickly and rudely. Your task is to try and get to the end of your telling!
The second time you use the technique in an intermediate or advanced class group the students in tens, with one student teller in each group. This is more student centred and is great fun. Loads of interrogative practice.
Warmly yours, in haste, Mario