In my humble opinion creating a first class answer is not something necessarily learned from a book with a subject like law, although it can help. It simply takes time to realise what is required of you after you leave school where you were given marks purely for blurting everything you could recall onto a piece of paper. That doesn't say that these books will not be helpful, but even if you follow them it is experience and taking advantage of the, admittedly often scarce, feedback you receive (in fact the feedback you receive is downright useless a lot of the time) which will eventually push your marks up. Personally I have never used any of the books mentioned above, but I am tempted to give them a quick flick to see if the techniques suggested match up to mine, by a strange coincidence.