This is a sheet which could be printed onto A3 (I did). I then placed on desks, ink for chromatography, a mixture of oil and water for immiscible liquids, and a 2 litre empty fizzy drink bottle full of air (labelled air). I asked the students how to separate these things. We discussed the difficulties and then I let them walk around the room to see examples of the set-up (except fractional distillation which I had an image of). The students then had to write their own flow charts with the hints. Seemed to create a good overview on which we have subsequently added more detail.