I don’t really have any tips as such to share but I usually work on my strongest points first, and ensure I got a good understanding before moving onto the writing element (weakest area).
I use the Osbourne books and find the workbook is very useful, as it consists of three mock exams. I usually attempt the first question on mock exam 1, try and gain an understanding where I went wrong and attempt the first question but on the second mock, and again on the third mock exam. After each question I always check my answers rather than doing the whole paper in one sitting, I find it stays fresh in my mind concentrating one area at a time and figuring out where I went wrong. Once I feel fairly confident I will work on the second question for all the mock exam papers and so forth. This method works quite well for me and I use the same approach with the AAT mock exams.
I use flash cards on a keyring and take that with me everywhere. Any questions where I went wrong I would make a note of it on the flash card no matter how small, e.g. formulas or how to work out certain calculations.
The writing questions isn’t my strongest area so am not sure how to tackle those efficiently. The AAT mock exam papers are useful and I have so far found most of the questions to be very similar to the real exam.
Sorry I couldnt be more helpful.