The Elements of Eloquence, by Mark Forsyth
A romp through the classical rhetorical figures (or the book's Wikipedia page here)
First, turns out the Greeks had names for all the techniques of writing/speaking that you just kind of... use, on your own, without thinking about it? Like polyptoton, repeating a word in different grammatical forms, as in the Beatles' Please Please Me -- the first is an adverb, the second is a verb, and yes I had to look that up six times to (hopefully) avoid embarrassing myself by getting it wrong.
I can sort-of imagine that having the figures of rhetoric drummed into you and repeated from a very early age could make you a better speaker and writer -- I'm generally of the opinion that modern Western education (as I experienced it, etc) under-emphasises the power of block-memorising and thereby internalising high-quality language. But I'm not sure how useful it is to read just one single book of this stuff -- I don't feel like (briefly) knowing the names of various figures is going to help me much.
And this brings me to one of my great obsessions: my view that most advice is bad advice because the difficult thing is not learning some rules or principles but knowing when to apply them. Forsyth is very good! He has a lovely pen, can turn a phrase, he makes me laugh. Often when describing a figure he'll fairly-cleverly incorporate that figure into his description of the figure (I say "fairly" clever only because at some point it becomes obvious that this is his game, and though he stays endlessly good at it I can't stay endlessly impressed). But I'm completely unconvinced that the principles of this book are why he's good at writing: I think a completely nebulous cloud of talent and/or judgement and/or experience has enabled him to apply the principles only when they're wanted and with suitable finesse.
This... this is my problem with almost-all theoretical writing, frankly? And when I write that out it seems obvious, banal, over-wrought, and yet.... this seems like one of the most important things in the world to me, and I don't know if everyone else agrees with me?