I would say don't rely on those IPM sample exams, those things are way easier than IT Apps. Learn how to write perfect Excel formulas (not in IPM), and learn how to answer those damn ethics questions
Agreed, don't waste your time on IPM exams when exam period is coming up. Only go through them if you have finished every other revision material you already have in your huge pile of practice exams and booklets.
Formulas, definitely. That includes: SUM, COUNT, COUNTIF, MAX, MIN, and importantly the VLOOKUP and IF formulas. It is highly unlikely that all of these will come up in the end of year exam, but there is bound to be one placed in there, as did the VLOOKUP and IF did for this year.
However, what I reckon is the most important thing for the final exams is to answer the question as required by the information problem. I cannot stress that enough. If the information problem is about a Primary School you produce an answer which will relate to a primary school. This maybe common sense, but you would be surprised how many people just write an answer which doesn't relate back to the information problem.
Finally, use common sense and sometimes don't think too much about the question. In this year's exams there were a couple dodgy questions (as with nearly ALL IT Applications exams and practice exams). There is likely to be a couple of questions where course knowledge cannot be applied, hence you must think on your feet and answer the question as appropriately as possible. For example, there was a question in this years final exam which asked you to organize web-pages into the correct categories for a school website. This is something examiners expect you to know through common sense. Personally I believe there are many ways to answer such an ambiguous question similar to this, and such questions shouldn't be included in the final exam. Nevertheless, in the end it is down to how you determine the question yourself, and of course answering it in a logical sense for examiners to credit you for the mark.
Well that's all I can think of now, I may post some more advice later. And if there's any other questions I'll be happy to help.