Oxymoron is a paradox reduced to two words, usually in an adjective-noun ("eloquent silence") or adverb-adjective ("inertly strong") relationship, and is used for effect, complexity, emphasis, or wit:
- I do here make humbly bold to present them with a short account of themselves and their art.....--Jonathan Swift
- The bookful blockhead, ignorantly read, / With loads of learned lumber in his head . . . .--Alexander Pope
- He was now sufficiently composed to order a funeral of modest magnificence, suitable at once to the rank of a Nouradin's profession, and the reputation of his wealth. --Samuel Johnson
Oxymoron can be useful when things have gone contrary to expectation, belief, desire, or assertion, or when your position is opposite to another's which you are discussing. The figure then produces an ironic contrast which shows, in your view, how something has been misunderstood or mislabeled:
- Senator Rosebud calls this a useless plan; if so, it is the most helpful useless plan we have ever enacted.
- The cost-saving program became an expensive economy.
Other oxymorons, as more or less true paradoxes, show the complexity of a situation where two apparently opposite things are true simultaneously, either literally ("desirable calamity") or imaginatively ("love precipitates delay"). Some examples other writers have used are these: scandalously nice, sublimely bad, darkness visible, cheerful pessimist, sad joy, wise fool, tender cruelty, despairing hope, freezing fire. An oxymoron should preferably be yours uniquely; do not use another's, unless it is a relatively obvious formulation (like "expensive economy") which anyone might think of. Also, the device is most effective when the terms are not common opposites. So, instead of "a low high point," you might try "depressed apex" or something.