There are various ways of flattering, and, of course, you must adapt your style to your subject. Some people like it laid on with a trowel, and this requires very little art. With sensible persons, however, it needs to be done very delicately, and more by suggestion than actual words. A good many like it wrapped up in the form of an insult, as—"Oh, you are a perfect fool, you are. You would give your last sixpence to the first hungry-looking beggar you met;" while others will swallow it only when administered through the medium of a third person, so that if C wishes to get at an A of this sort, he must confide to A's particular friend B that he thinks A a splendid fellow, and beg him, B, not to mention it, especially to A. Be careful that B is a reliable man, though, otherwise he won't.
Jerome K. Jerome