Hey I finished my ATPLs in Feb this year and did them in 2 sittings over 5 1/2 months which I thought was quite a push, seeing as there is so much to learn.
People in the past have said that the best method is to hammer the question bank, but that is becoming a less favourable tactic as the questions are being changed. I would say that for certain subjects, question bank hammering is quite favourable, for example I found it very useful for Comms, Air Law, Ops, HPL and even Rnav. By that I mean, it was my main source of revision for said subjects.
I then found that for subjects such as Gnav, M & B and Flight Planning where there isn't particularly a large pile of information to handle, but a very good understanding of how to carry out tasks is required, it was best to go over your material so as to understand the facts (Variation, Grivation, winter solstice, moments, c of g movement etc) and then use the question bank to practise answering questions so that you can improve your speed and focus on how you got the answer rather than what the answer is.
Then for other subjects I used the question bank to supplement what I learnt from the material, I would make sure not to dive straight into it and learn the content beforehand. Believe me, its much easier to answer a met question when you know exactly why it happens. Though, once I had gone through all the material I would just hammer the question bank and if the banks explanations were not sufficient, I would just consult the CBT I had.
I found that the four hardest subjects were Instrumentation, POF, Air Law (Yes I know....but it was just sooooo boring!) and maybe RNav?
The moral of the story is: Stay on top of things, work in manageable chunks, disregard clearly irrelevant facts to passing the exams(You can learn all those once you have passed your exams) and approach with an open mind.