for P&H - get a syllabus dot point and come up with heaps of evidence/points for it, i.e. entertainment - i wrote about the theatres, amphitheatre, palaestrae, baths etc and what it shows us about society. and the final question always comes from the last part of the syllabus, i.e. new research techniques and technology was last year's question. they could ask about conservation/preservation, contributions of archaeoloists, impact of tourism, ethical issues etc just know that section REALLY well.
historical period - i basically come up with evidence for each of the dot points and write practice essays, since there's a limit to what they can ask.
personality - once again it's pretty limited, so i come up with potential questions and do them. that might not sound effective, a lot of evidence for one question can overlap with another, between a few good questions you cover pretty much everything.
ancient society - basically the same as P&H but with quotes, also past papers, and ensure you know the syllabus well.
find the patterns in the questions
i do this too. if the dot point hasn't shown up, chances are it will. specimen papers are good, for example, look at the questions for my topics in the specimen and HSC:
historical period question for Unification -> First Intermediate Period
2006 specimen; assess the reasons for the breakdown of Old Kingdom Egypt
2007 HSC; evaluate factors contributing to the breakdown of the Old Kingdom
personality question for Hatshepsut
2006 specimen; assess H's relationship with Thut III (15 marks)
2007 HSC; describe the relationship between H and Thut III (10 marks)
Pompeii and Herculaneum is a similar story.
Question 2 (8 marks)
2006 specimen; using sources 3 and 4 and your knowledge of other sources, interpret what these reveal about religion in P&H (sources; lares shrine, Imperial cult altar)
2007 HSC; using sources 3 and 4.... describe what the evidence shows about religion in P&H (source; statue with lares on either side, temple of Isis)
Question 3
2006 specimen;
Using source 5 and other sources, evaluate the methods of investigating P&H
2007 HSC
Using source 5, 6 and your knowledge of other sources, assess the different methods used by archaeologists over time to investigate P&H
i hope you're seeing the pattern. different wording, different sources, essentially the exact same topic. in other words, do the specimen papers.