If doubtful whether to end with "yours faithfully," or "yours truly," or "yours most truly," &c. (there are at least a dozen varieties, before you reach "yours affectionately"), refer to your correspondent's last letter, and make your winding-up at least as friendly as his: in fact, even if a shade more friendly, it will do no harm!
Lewis CarrollOne of the deepest motives (as you are aware) in the human beast (so deep that many have failed to detect it) is Alliteration.
Lewis Carroll