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 CarrollYou're not the same as you were before," he said. You were much more... muchier... you've lost your muchness.
Lewis Carroll