The great enemy of truth is very often not the lie--deliberate, contrived, and dishonest--but the myth--persistent, persuasive, and unrealistic.
--John F. Kennedy
If you're looking for examples of good writing and speaking technique, JFK's speeches are a reliable goldmine. And the quote above is an excellent example of three easy-to-use techniques for memorable turns of phrase:
1) The rule of three
Everything works better in threes. Arguments carry more weight, sentences are more memorable, jokes are funnier. Kennedy's quote above uses the rule of three twice.
Note the two nested parallel clauses in the quote above: not the lie/but the myth and deliberate, contrived, and dishonest/persistent, persuasive, and unrealistic. Sentences with parallel structures stay in your readers' minds.
Finally, note the nuanced alliteration in the phrases deliberate, contrived, and dishonest and persistent, persuasive, and unrealistic. Note that a little alliteration goes a long way, and too much alliteration sounds contrived. Had Kennedy used three consecutive alliterative words in these phrases it would have been overkill.