I'm talking about Edexcel here but...
I'd say that it is mostly knowledge of both human and physical that you need before going into this exam, which you should mostly know from revising the first two papers. It is also important to know which AO skills you will need for each question. For example in the 8 mark analyse questions you need AO1 and AO3, 4 marks for each AO.
I hope this helps, this is just how I've been revising for it!