One of the things that I get way too excited about is finding meaning in grammar and rhetoric. I haven't studied this stuff extensively, but I love discovering how words and their usage can reflect and enhance meaning and tone.
Quick overview: I'm thinking specifically about rhetorical schemes of repetition and construction, and although it may sound intimidating and the terminology sounds like a cross between Latin and Klingon, the stuff is awesome. When rhetorical schemes are done right, they are effective and exciting and evocative (1, see below).
When I first learned about rhetorical schemes, it was so much fun, I felt like a child slinging mud. Like a child slinging mud, however, it was chaos and I didn't know what I was doing (2). Anaphora was my favorite, and I dumped it on my writing like sugar in my coffee.
In the end, these are a few more tools to throw in your toolbox. Use them. Use them wisely. Oh, and have as much fun as I imagine e. e. cummings must have felt when he realized he could throw in a comma wherever he wanted. Like a kid throwing mud.
(1) All right, I'm showing off here. Certainly, this is assonance, which is the repetition of vowel sounds. Assonance, depending on the vowel sound, may enhance a mood, like "ee" sounds can be whiny or tedious but "oo" sounds can be haunting or soothing. This is also a polysyndeton, a repetition of conjunctions (and, or, so, or but). The typical use of a polysyndeton is to show tediousness or something that just keeps going on and on and on and on (well, you get the point). You might even classify this as a close isocolon, but the syllables are a little off.
(2) Anadiplosis. Repeating the last word or phrase in the beginning of the next sentence.
(3) Couldn't resist. Anaphora. "If you do it..." is the beginning of both sentences. Anaphora can have different purposes, but generally, the intention of anaphora is to juxtapose. The beginning of the sentence is the same, so the rest of the sentence will be different, setting up some sort of comparison.