Same as any other really.... prepare well (ie consider marking if you find it tough, do a mock and lots of exam practise) and understand the material rather than be able to slavishly regurgitate. Its the last bit that helps on a 'difficult' paper. Just because a subject has a low pass rate doesn't mean you'll find it hard. Everyone has a different stumbling block so go at it with a positive attitude. That too helps.
Try doing past exam papers under exam conditions....this paper has one difficulty : throws as many varied type of problems as one can imagine...so better prepare urself for novel problems....other thing is that only when you start applying the techniques you will appreciate their use, as the bookwork is limited in examples as well as contents
one mistake I did with my past approach to CT4, was answering all the descriptive type questions at first. the descriptive type questions are probably marked subjectively...then I run out of time to finish calculations on the very long last question. what I should have done, was answering all the big questions first and leave the descriptive till the end. I am never sure how comprehensive my answer should be to gain full marks. maybe I am writing too much and I run out of time....
for descriptive type answers, best way to go is to see how examiners write , in past exam papers answer reports. This really helps to understand how much is good enough, keeping in mind the marks asociated with such questions..
problem is that the questions vary and the answers vary... and the length required and grading must vary as well.
In the Cts there isn;'t that much subjectivity cf the later subjectives. But get in the habit of writing succinctly and don't say the same thing twice but just reworded. Highlight the keywords eg use capitals. On long numerical qns leave an audit trail so if the maths goes wrong you pick up the method marks. If you find timing hard, all the more reason to put yourself under the same time pressure in your prep.
Sorry... the other thing write in proportion to available marks. 3 marks doesn't warrant a 3 page essay for example. 10 marks wants more than 5 marks etc.
Its like if you have an equation, pv premiums = pv benefits + pv expenses, write that so you know what you are adding together. Work out each bit separately : pv benefits then the numerics for that bit. When working with probabilities if you have the probability of something happening, and you want the opposite say so. ie 1- answer you have. If its just numbers on a page, an examiner can't see you train of thought. If they can, thats where you'll start to get most method marks.