Prepare worksheets for all students as well as enlarged worksheets for the ALT and the JTE.
Explain or demonstrate the grammar point with the JTE.
Tell the students they are going to do a 'sign game with gestures' and please watch while you demonstrate.
Make a pair with the JTE and greet each other. Then play 'rock scissors paper' the winner shows the loser their worksheet. The loser picks a square that hasn't been signed and does the gesture that matches that square. For example the JTE pretends to do kendo. The winner then asks 'are you doing kendo?' and the loser says 'yes, I am' the winner thens says 'sign please',the loser signs, they say goodbye and move on to make a new pair.
I usually do the demonstration twice and then practice the vocabulary and then move onto the activity. To help make the mood I often do all the gestures and the students shout out the questions.
I usually continue the activity until a few students are done or 5 minutes. Sometimes when students are done I stamp their page.
I find the students enjoy this activity although like any mingling activity you shouldn't let it go to long.