Let's talk about schemes. Not schemes of the nefarious sort, but schemes of word order.
There are various types, including schemes of repetition ("I have a dream that one day … I have a dream that one day …"), schemes of inversion (Yoda's "Anger, fear, aggression; the dark side of the Force are they"), and schemes of omission (as in "I wrote the first draft, Brandi the second").
If you want to get fancy, you can use the Greek words Plato and Aristotle used for two schemes of repetition: antimetabole and chiasmus.
Antimetabole is the repetition of words in reverse order, as in "Everyone who loves his country is a patriot, but not every patriot loves his country."
Chiasmus is the repetition of grammatical structures without repetition of the same words or phrases, as in "It's hard to make time, but to waste it is easy."
Still breathing? Good. The hard part is behind you. Now that you know the concepts, you can have some fun with sentences. Let's take two of them apart.
"Ask not what your country can do for you; ask what you can do for your country" is not only an inversion, but also an antimetabole (or repetition of words in reverse order). Here, if C = country and Y = you, then the order is CY/YC:
"Ask not what your country (C) can do for you (Y); ask what you (Y) can do for your country (C)."