Passed my PPL theory exam last week.... 95%! Pretty happy with that! In the spirit of giving back, for those embarking on PPL theory study I have a few suggestions:
(1) Know your resources
Become familiar with
* ERSA (buy your own copy)
* AIP (buy your own copy)
* CAOs & CARs (borrow from your flight school)
* VFR Guide (buy/print your own copy)
Read the VFR Guide so you know what it contains, but don't stop there. The VFRG will reference the official docs and it's definitely worth taking the time to locate the particular provisions in the official document during your study. So if you're studying separation minima, by all means find the answer in the VFRG, but then go find in the answer in the AIP. If you're thinking through requirements for an alternate or some specific arrangement relating to carriage of pax, know where to go for the detailed, specific information which will not necessarily be covered in the VFRG. You will get some really specific questions in the exam - don't be caught out.
The VFRG is just a guide - someone else's summarisation of the ERSA, AIP etc. You're going to be a better pilot if you're across the ERSA, AIP/other regs and don't need to rely on an unofficial summarisation.
In the ERA, AIP and VFRG, highlight important sections and tag materials so you can find important things quickly.
(2) Practice, practice, practice
Do all the practice questions you can get your hands on. I'd recommend a couple of different sources for questions (ie. don't use practice questions only from the one provider). I decided against doing a theory course and used self-study materials only, including the Bob Tait PPL book and the Dyson-Holland PPL Sample Exam Set. The questions in the Bob Tait book are good indicators of the style and difficulty of the questions in the actual exam. The Dyson-Holland questions, however, were more difficult but this is what makes them a very good study resource - the increased question difficulty really forces you to know your stuff.
Be sure to spend ~3 hours going back over the BAK/RPL theory book - this is foundation knowledge and you can expect basic aero knowledge questions on the PPL exam: Forces on an aircraft in flight, coefficient of lift, L/D ratio, impact of load factor on stall speed, headwinds/tailwinds, engines etc.
(3) Knock your theory over early
Don't leave the theory until the last minute. Study up, get it out of the way, and then concentrate on the flying (and using the theory).
(4) Use time wisely
You have 3 hours and 30 mins, that's 210 mins, to complete the exam. Most questions are worth 1 mark and there will be a few worth 2 marks for a total of 60 marks. This means you can expect ~55 questions. Your "earn rate" therefore needs to be one mark every 3.5 minutes (210 mins / 60 marks). However, many questions will not take nearly this long - they're the sort of questions where you either know the answer or you don't. Time saved on these questions can be used on some of the more difficult questions (or to look up details in one of the allowed resources).
On a piece of scratch paper, keep a note of those questions where you are not sure of your answer. Once you've finished the first run through the exam, you can then go back to these particular questions. If you're confident of an answer the first time around, I would not suggest going back to it (your first answer is probably your best).
With 210 minutes, time will not be an issue (if you find you're short of time, you haven't studied nearly enough). Expect to complete the exam (first pass) in about 120 minutes, leaving plenty of time to review your calcs, check questions where you're not sure and then relax.