I split mine in to 4 sittings. 4, 4, 3, 3. Starting with the hardest and finishing with the easiest to allow any failures to cascade, with the option of another 2 sittings if needed. They weren't.
A natural procrastinator, I can only work under pressure. The best and decision I made was to throw caution to the wind and pay for the exams before opening a single book.
So I booked 4 exams the following month. 2 on Monday and 2 on Thursday. Then I studied one subject per week, Frank Abignale style. The two most recent subjects I took on Monday morning. Then I made use of the next 2½ days to revise the other subjects and took them on Thursday afternoon.
Using a combination of CATS online, BGS, Google and YouTube I managed to average 7 days per subject.