I usually have student do this after they complete the graphic organizers on the two different perceptions of the ministries in 1984. (This graphic organizer is also available on my teacherspayteachers site.)
I split students into groups of three and give each a group a half sheet of directions that indicate what ministry and what "side" of the ministry they are representing (what the ministry says they do or what the ministry really does). Each group creates a poster for their designated ministry and side following the same four basic components. I also created a group for the proles and inner party so there are 10 different set of directions to cover most class sizes.
I usually make sample posters for them creating a poster for teachers - one showing what teachers/schools say they do and the other poster what they "really" do (or what students like to think they do). Students really like those and it gives them a good idea of what they need to create.